Auto PR Label Conflicts (#2185)

* Update README.md

* Revert "Update README.md"

This reverts commit 78805b973e5ba5c1b3639db66ac849e70c636f57.

* Add files via upload

.github/workflows/conflicts.yml

@@ -0,0 +1,22 @@
+name: "Conflicts"
+on:
+  # So that PRs touching the same files as the push are updated
+  push:
+  # So that the `dirtyLabel` is removed if conflicts are resolve
+  # We recommend `pull_request_target` so that github secrets are available.
+  # In `pull_request` we wouldn't be able to change labels of fork PRs
+  pull_request_target:
+    types: [synchronize]
+
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    steps:
+      - name: check if prs are dirty
+        uses: eps1lon/actions-label-merge-conflict@releases/2.x
+        with:
+          dirtyLabel: "PR: merge conflicts / rebase needed"
+          removeOnDirtyLabel: "PR: waiting for review"
+          repoToken: "${{ secrets.GITHUB_TOKEN }}"
+          commentOnDirty: "This pull request has conflicts, please resolve those before we can evaluate the pull request."
+          commentOnClean: "Conflicts have been resolved. A maintainer will review the pull request shortly."