Add sort limit to $sort (aggregation) and cursor.sort() (#801)

* Adding sort limit in a few places

* Resolving comment

Co-authored-by: Ashley Brown <[email protected]>

Author: mdb-ashley

source/includes/sort-limits.rst

@@ -0,0 +1 @@
+You can sort on a maximum of 32 keys.

source/reference/limits.txt

@@ -254,6 +254,13 @@ Indexes
    - You cannot use :method:`~cursor.hint()` on a :doc:`hidden index
      </core/index-hidden>`.
 
+Sorts
+-----
+
+.. limit:: Maximum Number of Sort Keys
+
+   .. include:: /includes/sort-limits.rst
+
 Data
 ----
 

source/reference/method/cursor.sort.txt

@@ -57,8 +57,13 @@ Definition
    existing fields <sort-asc-desc>` or :ref:`sort on text score metadata
    <sort-metadata>`.
 
-Behaviors
----------
+Behavior
+--------
+
+Limits
+~~~~~~
+
+.. include:: /includes/sort-limits.rst
 
 .. _sort-cursor-consistent-sorting:
 

source/reference/operator/aggregation/sort.txt

@@ -53,6 +53,11 @@ Definition
 Behavior
 --------
 
+Limits
+~~~~~~
+
+.. include:: /includes/sort-limits.rst
+
 .. _sort-aggregation-consistent-sorting:
 
 Sort Consistency