Document Hazelcast module

[artembilan]

The spring-integration-hazelcast extension project has been migrated to the respective module in this project.

Add documentation (hazelcast.adoc) for this module.
The structure of the file can be taken from other similar modules, e.g. gemfire.adoc.
The content for the doc can be obtained from existing README for the extension project: https://github.com/spring-projects/spring-integration-extensions/tree/main/spring-integration-hazelcast#readme