docs(config options): automerge and GitHub branch protection rule (#…

…25810)

Co-authored-by: Oliver Salzburg <oliver.salzburg@protonmail.com>
Co-authored-by: Rhys Arkins <rhys@arkins.net>

docs/usage/configuration-options.md

@@ -205,6 +205,16 @@ So for example you could choose to automerge all (passing) `devDependencies` onl
     Renovate tries to delay until Azure is in the expected state, but it will continue if it takes too long.
     In some cases this can result in a dependency not being merged, and a fresh PR being created for the dependency.
 
+**Automerge and GitHub branch protection rules**
+
+You must select at least one status check in the _Require status checks to pass before merging_ section of your branch protection rules on GitHub, if you match all three conditions:
+
+- `automerge=true`
+- `platformAutomerge=true`, Renovate defaults to `true`
+- You use use GitHub's _Require status checks to pass before merging_ branch protection rule
+
+If you don't select any status check, and you use platform automerge, then GitHub might automerge PRs with failing tests!
+
 ## automergeComment
 
 Use this only if you configure `automergeType="pr-comment"`.