Lockdown Pull Requests on subrepositories (#7)

Author: yann-eugone

.github/workflows/lockdown.yml

@@ -0,0 +1,27 @@
+name: 'Lock down Pull Requests'
+
+on:
+  pull_request:
+    types: opened
+
+jobs:
+  lockdown:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dessant/repo-lockdown@v2
+        with:
+          github-token: ${{ github.token }}
+          close-pr: true
+          lock-pr: true
+          pr-comment: >
+            Thanks for your pull request!
+
+            However, this repository does not accept pull requests,
+            see the README for details.
+
+            If you want to contribute,
+            you should instead open a pull request on the main repository:
+
+            https://github.com/yokai-php/batch-src
+
+            Thank you