Documentation updates: Links to serialization post and increasing the 1MB message size limit

Author: rozza

docs/sink.md

@@ -117,6 +117,8 @@ _Note: Even when using RAW JSON mode i.e. with
 [StringConverter](https://kafka.apache.org/21/javadoc/index.html?org/apache/kafka/connect/storage/StringConverter.html) the expected 
 Strings have to be valid JSON._
 
+See the excellent Confluent post [serializers explained](https://www.confluent.io/blog/kafka-connect-deep-dive-converters-serialization-explained)
+for more information about Kafka data serialization.
 
 ### Supported Sink Record Structure
 Currently the connector is able to process Kafka Connect SinkRecords with

docs/source.md

@@ -20,6 +20,10 @@ Data is read from MongoDB using the configuration connection as specified in the
 
 Currently, only JSON strings are supported as the output.
 
+**Note:** Kafka defaults to a 1MB message size. If the JSON string size of the change stream document is greater that 1MB then you will need
+to configure Kafka to handle larger sized documents.  See this [stackoverflow post](https://stackoverflow.com/questions/21020347/how-can-i-send-large-messages-with-kafka-over-15mb)
+for more information.
+
 #### Event Document Format
 
 The following document represents all possible fields that a change stream response document can have: