add missing changelog entry, fix typo

Author: Divjot Arora

source/client-side-encryption/tests/README.rst

@@ -127,7 +127,7 @@ Each YAML file has the following keys:
 
     - ``result``: Same as the Transactions spec test format with one addition: if the operation is expected to return
       an error, the ``result`` document may contain an ``isTimeoutError`` boolean field. If ``true``, the test runner
-      MUST assert that the error represents a timeout due to the use of the ``timeoutMS`` operation. If ``false``, the
+      MUST assert that the error represents a timeout due to the use of the ``timeoutMS`` option. If ``false``, the
       test runner MUST assert that the error does not represent a timeout.
 
   - ``expectations``: |txn|

source/transactions-convenient-api/tests/README.rst

@@ -212,6 +212,8 @@ should be checked:
 Changelog
 =========
 
+:2021-04-29: Remove text about write concern timeouts from prose test.
+
 :2019-03-01: Add top-level ``runOn`` field to denote server version and/or
              topology requirements requirements for the test file. Removes the
              ``minServerVersion`` top-level field, which is now expressed within