Note SCRAM-SHA-256 in error docs (#1519)

Author: jmikola

src/libmongoc/doc/errors.rst

@@ -91,7 +91,7 @@ Many C Driver functions report errors by returning ``false`` or -1 and filling o
 +-----------------------------------------+----------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 |                                         | ``MONGOC_ERROR_GRIDFS_BUCKET_STREAM``                                                                                            | An error occurred on a stream created from a GridFS operation like :symbol:`mongoc_gridfs_bucket_upload_from_stream`.                                                                                                                                                                                                    |
 +-----------------------------------------+----------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
-| ``MONGOC_ERROR_SCRAM``                  | ``MONGOC_ERROR_SCRAM_PROTOCOL_ERROR``                                                                                            | Failure in SCRAM-SHA-1 authentication.                                                                                                                                                                                                                                                                                   |
+| ``MONGOC_ERROR_SCRAM``                  | ``MONGOC_ERROR_SCRAM_PROTOCOL_ERROR``                                                                                            | Failure in SCRAM-SHA-1 or SCRAM-SHA-256 authentication.                                                                                                                                                                                                                                                                  |
 +-----------------------------------------+----------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 | ``MONGOC_ERROR_SERVER_SELECTION``       | ``MONGOC_ERROR_SERVER_SELECTION_FAILURE``                                                                                        | No replica set member or mongos is available, or none matches your :doc:`read preference <mongoc_read_prefs_t>`, or you supplied an invalid :symbol:`mongoc_read_prefs_t`.                                                                                                                                               |
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