docs: update release docs (#1301)

* docs: update release docs

* docs: correct tag is fix, not bug

docs/contributing.md

@@ -135,9 +135,12 @@ If a proto block _begins with_ a comment that says only `Incorrect.` or
 
 ## Releases
 
-Releases are handled automatically by [release-please][]. If a manual release
-is desired, simply open a pull request with an empty commit and the proper
-conventional commit message for the desired semver bump. For example:
+Releases are handled automatically by [release-please][] by sending PRs
+after changes starting with `fix:` or `feat:` have been merged.
+[example release pr][].
+
+If a manual release is desired, simply open a pull request with an empty commit
+and the proper conventional commit message for the desired semver bump. For example:
 
 ```sh
 # releasing a minor version
@@ -156,4 +159,5 @@ git commit --allow-empty -m 'fix: new patch release'
 [`rules.go`]: https://github.com/googleapis/api-linter/blob/main/rules/rules.go
 [visitor pattern]: https://en.wikipedia.org/wiki/Visitor_pattern
 [release-please]: https://github.com/googleapis/release-please
+[example release pr]: https://github.com/googleapis/api-linter/pull/1290
 <!-- prettier-ignore-end -->