DOCSP-17218 whats new4.3 (#131)

* Added what's new in 4.3

Author: kyuan-mongodb

source/whats-new.txt

@@ -25,9 +25,9 @@ What's New in 4.3
 New features of the 4.3 Java driver release include:
 
 - MongoDB Versioned API. For more information, see our :doc:`Versioned API guide </fundamentals/versioned-api>`. 
-- Added a ``setWindowFields`` pipeline stage to allow the use of window operators 
+- Added a builder API for the ``setWindowFields`` pipeline stage to allow the use of window operators 
 - Added support for setting Netty `io.netty.handler.ssl.SslContext <https://netty.io/4.1/api/io/netty/handler/ssl/SslContext.html>`__
-- Added ``snapshot`` (non-speculative) as a ``readConcern`` level for read commands outside of transactions
+- Added support for snapshot reads to ``ClientSession``
 - Limited the rate of establishing new connections per connection pool
 - Removed most restrictions on allowed characters in the field names of documents you insert or replace. This is a behavioral change for any application that is relying on client-side enforcement of these restrictions.
 
@@ -63,7 +63,7 @@ in the field names of documents:
 
    Unacknowledged writes using dollar-prefixed or dotted keys may
    be silently rejected by pre-5.0 servers, where some restrictions on
-   field names are still enforced in the serve.
+   field names are still enforced in the server.
 
 .. _version-4.2:
 
@@ -74,9 +74,9 @@ New features of the 4.2 Java driver release include:
 
 - Added Azure and GCP key stores to client-side field level encryption
 - Added Kerberos caching tickets for reuse in multiple authentication requests- Added `MongoClients <http://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-sync/com/mongodb/client/MongoClients.html>`_ instances with ``MongoClientSettings`` or ``ConnectionString`` as the configuration
--  The ``explain()`` method can now be used on `find <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-sync/com/mongodb/client/FindIterable.html#explain()>`_ and `aggregate <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-sync/com/mongodb/client/AggregateIterable.html#explain()>`_ commands
+- Use of the ``explain()`` method on `find <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-sync/com/mongodb/client/FindIterable.html#explain()>`_ and `aggregate <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-sync/com/mongodb/client/AggregateIterable.html#explain()>`_ commands
 - Added a `JsonObject <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/bson/org/bson/json/JsonObject.html>`_ class to make encoding from and decoding to JSON more efficient by avoiding an intermediate Map representation
-- Added a `BsonRepresentation <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/bson/org/bson/codecs/pojo/annotations/BsonRepresentation.html>`_ annotation that allows ``ObjectId`` BSON values to be represented as a ``String`` in `POJO <https://en.wikipedia.org/wiki/Plain_old_Java_object>`_ classes
+- Added a `BsonRepresentation <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/bson/org/bson/codecs/pojo/annotations/BsonRepresentation.html>`_ annotation that allows you to represent the``ObjectId`` BSON values as a ``String`` in `POJO <https://en.wikipedia.org/wiki/Plain_old_Java_object>`_ classes
 - Added a `Filters.empty() <https://mongodb.github.io/mongo-java-driver/4.2/apidocs/mongodb-driver-core/com/mongodb/client/model/Filters.html#empty()>`_ method
 
 .. important::