Edited aggregation pipeline doc, added that you can adjust stage width (#345)

* Edited aggregation pipeline doc, added that you can adjust stage width

* copy review

Author: JuliaMongo

source/aggregation-pipeline-builder.txt

@@ -14,65 +14,59 @@ Aggregation Pipeline Builder
 
 *New in version 1.14.0*
 
-The Aggregation Pipeline Builder in |compass| provides the ability to
-create :manual:`aggregation pipelines </core/aggregation-pipeline/>` to
-process data. With aggregation pipelines, documents in a collection
-or view pass through multiple stages where they are processed into a
-set of aggregated results. The particular stages and results can be
-modified depending on your application's needs.
+Create :manual:`aggregation pipelines </core/aggregation-pipeline/>` to
+process data. In aggregation pipelines, documents in a collection
+or view pass through stages where |compass| processes them into a
+set of aggregated results. You can change the stages and results to
+suit your needs.
 
-To access the aggregation pipeline builder, navigate to the
-:doc:`collection or view </collections>` for which you wish to create an
-aggregation pipeline and click the :guilabel:`Aggregations` tab. You
-are presented with a blank aggregation pipeline. The
-:guilabel:`Preview of Documents in the Collection` section of the
-:guilabel:`Aggregations` view displays 20 documents sampled from the
-current collection.
+To start building an aggregation pipeline for a :doc:`collection or view
+</collections>`, choose the collection and click the
+:guilabel:`Aggregations` tab.
+A blank aggregation pipeline displays. The :guilabel:`Preview of
+Documents in the Collection` section of the :guilabel:`Aggregations`
+view displays 20 documents sampled from the current collection.
 
-To populate the Aggregation Pipeline Builder, you can either:
+You can:
 
-- :ref:`Create a new Aggregation Pipeline in the UI <create-agg-pipeline>`,
+- :ref:`Create a new aggregation pipeline <create-agg-pipeline>`
 
-- :ref:`Open a saved pipeline <open-saved-pipeline>`, or
+- :ref:`Save a pipeline <save-agg-pipeline>`
 
-- :ref:`Import a Pipeline from Plain Text <compass-import-pipeline>`
+- :ref:`Open a saved pipeline <open-saved-pipeline>`
 
-.. _create-agg-pipeline:
+- :ref:`Set the documents limit or auto preview documents <use-sample-mode-or-auto-preview>`
 
-Create an Aggregation Pipeline
-------------------------------
+- :ref:`View or change pipeline settings <change-pipeline-settings>`
 
-.. include:: /includes/steps/create-agg-pipeline.rst
+- :ref:`Specify custom collation <pipeline-custom-collation>`
 
-.. _pipeline-custom-collation:
+- :ref:`Create a view from pipeline results <create-a-view>`
 
-Specify Custom Collation
-~~~~~~~~~~~~~~~~~~~~~~~~
+- :ref:`Import a pipeline from plain text <compass-import-pipeline>`
 
-Use :manual:`custom collation </reference/collation/>` to specify
-language-specific rules for string comparison, such as rules for
-letter case and accent marks.
+- :ref:`Export a pipeline to Java, Node, C#, and Python 3 <compass-export-pipeline>`
 
-To specify a custom collation:
+Limitations
+-----------
 
-#. Click the :guilabel:`Collation` button at the top of the pipeline
-   builder.
+The :pipeline:`$out` stage is not available if you are connected to a
+`Data Lake <https://www.mongodb.com/atlas/data-lake>`__.
 
-#. Enter your collation document.
+.. _create-agg-pipeline:
 
-Limitations
-~~~~~~~~~~~
+Create an Aggregation Pipeline
+------------------------------
 
-The :pipeline:`$out` stage is not available if you are connected to a
-`Data Lake <https://www.mongodb.com/atlas/data-lake>`__. 
+.. include:: /includes/steps/create-agg-pipeline.rst
 
 .. _save-agg-pipeline:
 
 Save a Pipeline
 ---------------
 
-You can save a pipeline so that you can access it later. If you
-load a saved pipeline, you can modify it without
+You can save a pipeline so that you can find it later. If you
+load a saved pipeline, you can change it without
 changing the original saved copy. You can also create a :ref:`view
 <view-details>` from your pipeline results.
 
@@ -85,20 +79,6 @@ To save your pipeline:
 
 #. Click :guilabel:`Save`.
 
-.. _create-a-view:
-
-Create a View from Pipeline Results 
------------------------------------
-
-.. note::
-
-   Creating a view from pipeline results does not save the pipeline
-   itself.
-
-To create a view from your pipeline results:
-
-.. include:: /includes/fact-create-view-from-pipeline.rst
-
 .. _open-saved-pipeline:
 
 Open a Saved Pipeline
@@ -111,11 +91,13 @@ Open a Saved Pipeline
 
 #. In the modal, click :guilabel:`Open Pipeline`.
 
-Pipeline Options
-----------------
+.. _use-sample-mode-or-auto-preview:
 
-The toggles at the top of the pipeline builder control the
-following options:
+Set the Documents Limit or Auto Preview Documents
+-------------------------------------------------
+
+Use the toggles at the top of the pipeline builder to set the
+limit on the number of sampled documents or to enable auto preview.
 
 .. list-table::
    :header-rows: 1
@@ -134,15 +116,17 @@ following options:
        preview documents pane to reflect the results of each active
        stage as the pipeline progresses.
 
-Pipeline Settings
-~~~~~~~~~~~~~~~~~
+.. _change-pipeline-settings:
+
+View or Change Pipeline Settings
+--------------------------------
 
-To view and modify pipeline settings:
+To view and change pipeline settings:
 
-1. Click the gear icon at the top right of the pipeline builder to
+1. Click the gear icon at the upper right of the pipeline builder to
    open the :guilabel:`Settings` panel.
 
-#. Modify the pipeline settings. The following settings can be modified:
+#. Change any of the following pipeline settings.
 
    .. list-table::
       :header-rows: 1
@@ -159,29 +143,60 @@ To view and modify pipeline settings:
         - 20
       * - .. data:: Max Time
         - Cumulative time limit in milliseconds for processing
-          the pipeline. Use this option to prevent long hang times.
+          the pipeline. Use this option to limit the waiting time if
+          the pipeline stops responding.
         - 5000
       * - .. data:: Limit
-        - When :guilabel:`Sample Mode` is enabled, number of documents
-          passed to :pipeline:`$group`, :pipeline:`$bucket`, and
+        - When :guilabel:`Sample Mode` is enabled, specifies the number of
+          documents passed to :pipeline:`$group`, :pipeline:`$bucket`, and
           :pipeline:`$bucketAuto` stages. Lower limits improve pipeline
-          execution time, but may miss documents.
+          running time, but may miss documents.
         - 100000
 
 #. Click :guilabel:`Apply` to save changes and close the
    :guilabel:`Settings` panel.
 
+.. _pipeline-custom-collation:
+
+Specify Custom Collation
+------------------------
+
+Use :manual:`custom collation </reference/collation/>` to specify
+language-specific rules for string comparison, such as rules for
+letter case and accent marks.
+
+To specify a custom collation:
+
+#. Click the :guilabel:`Collation` button at the top of the pipeline
+   builder.
+
+#. Enter your collation document.
+
+.. _create-a-view:
+
+Create a View from Pipeline Results
+-----------------------------------
+   
+.. note::
+
+   Creating a view from pipeline results does not save the pipeline
+   itself.
+
+   To create a view from your pipeline results:
+
+   .. include:: /includes/fact-create-view-from-pipeline.rst
+
 Example
 -------
 
-The following example walks through creating and executing a pipeline
-for a collection containing airline data. You can download this
+In this example, you create and run a pipeline
+for a collection with airline data. You can download this
 dataset from the following link:
 `air_airlines.json <https://raw.githubusercontent.com/mongodb/docs-assets/compass/air_airlines.json>`__.
 
 For instructions on importing JSON data into your cluster, see
 :manual:`mongoimport </reference/program/mongoimport/>`. This
-procedure assumes you have the data in the
+example assumes you have the data in the
 ``example.air_airlines`` namespace.
 
 
@@ -193,12 +208,11 @@ The following pipeline has two aggregation stages:
 
 - The ``$group`` stage groups documents by their
   ``active`` status and ``country``. The stage also adds
-  a new field called ``flightCount`` containing the number
+  a new ``flightCount`` field containing the number
   of documents in each group.
 
-- The ``$match`` stage filters documents to only return
-  those with a ``flightCount`` value greater than or
-  equal to ``5``.
+- The ``$match`` stage filters documents to return documents
+  with a ``flightCount`` value greater than or equal to ``5``.
 
 .. figure:: /images/compass/agg-builder-full-example.png
    :alt: Aggregation Builder Full Example
@@ -207,18 +221,18 @@ Copy the Pipeline to the Clipboard
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 1. Click the :guilabel:`Export to Language` button at the top
-   of the pipeline builder. The button opens the following modal:
+   of the pipeline builder. The following page displays:
 
    .. figure:: /images/compass/agg-builder-example-export-to-node.png
       :alt: Aggregation Builder Full Example
 
 #. Click the :guilabel:`Copy` button in the :guilabel:`My Pipeline`
-   panel on the left. This button copies your pipeline to your
+   panel on the left. |compass-short| copies the pipeline to your
    clipboard in :binary:`~mongo` shell syntax. You will use the
    pipeline in the following section.
 
-Execute the Pipeline
-~~~~~~~~~~~~~~~~~~~~
+Run the Pipeline
+~~~~~~~~~~~~~~~~
 
 1. Launch and connect to a
    :manual:`mongod </reference/program/mongod/>` instance which contains the imported ``air_airlines.json`` dataset.
@@ -230,7 +244,7 @@ Execute the Pipeline
 
       use example
 
-#. Run the following command to execute the pipeline created in
+#. Run the following command to run the pipeline created in
    |compass-short|:
 
    .. code-block:: javascript
@@ -253,8 +267,7 @@ Execute the Pipeline
         }
       }])
 
-The following is an excerpt of the documents returned by
-the pipeline:
+The pipeline returns documents, as shown in the following abbreviated example:
 
 .. code-block:: javascript
 

source/includes/steps-create-agg-pipeline.yaml

@@ -3,7 +3,7 @@ level: 4
 ref: add-pipeline-stage
 content: |
 
-   In the aggregation pipeline pane in the bottom-left of the view,
+   In the aggregation pipeline pane in the lower-left corner,
    click the :guilabel:`Select...` dropdown and select the
    :manual:`aggregation pipeline stage
    </reference/operator/aggregation-pipeline/>` to use for the first
@@ -16,10 +16,10 @@ title: Fill in the pipeline stage.
 level: 4
 ref: fill-in-stage
 content: |
-   Fill in your selected stage. As you modify the pipeline stage, the
-   preview documents shown in the pane to the right of the stage
-   update automatically to reflect the results of your pipeline as it
-   progresses, provided :guilabel:`Auto Preview` is enabled:
+   Fill in your selected stage. If you enable :guilabel:`Auto Preview`,
+   preview documents update automatically to the right of the stage to
+   reflect the results of your pipeline as it progresses. You can adjust
+   the width of the pipeline stage by dragging its border to the right.
 
    .. figure:: /images/compass/agg-builder-match-stage.png
       :alt: Aggregation Builder match stage example
@@ -29,8 +29,8 @@ title: Add additional pipeline stages.
 level: 4
 ref: add-additional-stages
 content: |
-   Add additional aggregation stages as desired by clicking the
-   :guilabel:`Add Stage` button below your last aggregation stage.
+   Click :guilabel:`Add Stage` to add additional aggregation stages
+   below your last aggregation stage.
    Repeat steps 1 and 2 for each additional stage.
 
    .. note::