Docs and Supported Configuration page should clearly indicate the DB2 connector is only supported on Linux

The documentation [1] and supported configuration page [2] should clearly indicate that the DB2 connector is only supported on Linux.  As part of DBZ-3303 the following line was added:

The connector requires the use of the abstract syntax notation (ASN) libraries, which are available as a standard part of Db2 for Linux. 

However the supported configurations should be clearly stated and added to the supported configurations page.

[1] https://access.redhat.com/documentation/en-us/red_hat_integration/2021.q1/html/debezium_user_guide/debezium-connector-for-db2

[2] https://access.redhat.com/articles/4938181