Add readme description

README.md

@@ -511,6 +511,15 @@ dependencies {
 
 ## Release notes
 
+### next
+
++ Added functionality for publisher confirmations to mitigate network issues for message producers.
++ New parameters are added to connection manager configuration:
+  + enablePublisherConfirmation - enables publisher confirmation. `false` by default.
+  + maxInflightPublications - the max number of unconfirmed published messages per channel. `200`, by default.
+  + heartbeatIntervalSeconds - rabbitmq connection heartbeat interval in seconds.
+    `0` by default (that means the default interval will be set by the internal library used to communicate with RabbitMQ). 
+
 ### 5.11.1-dev
 
 + Add `remove` and `clear` operations to `MapBuilder`