Improve clarity on deprecation of TCP replication

Borrows some text from #13647
for the changelog.

CHANGES.md

@@ -5,7 +5,15 @@ No significant changes since 1.66.0rc2.
 
 Deployments with multiple workers should note that the direct TCP replication
 configuration was deprecated in Synapse v1.18.0 and will be removed in Synapse
-v1.67.0. See the [worker documentation](https://matrix-org.github.io/synapse/v1.66/workers.html)
+v1.67.0. In particular, the TCP `replication` listener and the
+`worker_replication_port` config option are deprecated.
+
+To migrate to Redis, add the [`redis` config](https://matrix-org.github.io/synapse/v1.66/workers.html#shared-configuration)
+and remove the TCP `replication` listener from config of the master and
+`worker_replication_port` from worker config. Note that a HTTP listener with a
+`replication` resource is still required.
+
+See the [worker documentation](https://matrix-org.github.io/synapse/v1.66/workers.html)
 for more details.
 
 

docs/usage/configuration/config_documentation.md

@@ -431,7 +431,7 @@ Sub-options for each listener include:
 
    * `metrics`: (see the docs [here](../../metrics-howto.md)),
 
-   * `replication`: (see the docs [here](../../workers.md)).
+   * `replication`: (deprecated as of Synapse 1.18, see the docs [here](../../workers.md)).
 
 * `tls`: set to true to enable TLS for this listener. Will use the TLS key/cert specified in tls_private_key_path / tls_certificate_path.