docs: minor clarification to release instructions (#18493)

Signed-off-by: Alyssa Wilk <[email protected]>

GOVERNANCE.md

@@ -98,7 +98,8 @@ or you can subscribe to the iCal feed [here](webcal:https://kubernetes.app.opsgenie.co
 * From the envoy [landing page](https://github.com/envoyproxy/envoy) use the branch drop-down to create a branch
  from the tagged release, e.g. "release/v1.6". It will be used for the
  [stable releases](RELEASES.md#stable-releases).
-* Monitor the AZP tag build to make sure that the final docker images get pushed along with
+* Tagging will kick off another run of [AZP postsubmit](https://dev.azure.com/cncf/envoy/_build?definitionId=11). Monitor that
+ tag build to make sure that the final docker images get pushed along with
  the final docs. The final documentation will end up in the
  [envoyproxy.github.io repository](https://github.com/envoyproxy/envoyproxy.github.io/tree/main/docs/envoy).
 * Update the website ([example PR](https://github.com/envoyproxy/envoyproxy.github.io/pull/148)) for the new release.