Add workflow to acknowledge opened pull requests

Author: iamdevdhanush

.github/workflows/pr-open-ack.yml

@@ -0,0 +1,22 @@
+name: Acknowledge Pull Request
+
+on:
+  pull_request:
+    types: [opened]
+
+jobs:
+  acknowledge-pr:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Post acknowledgement comment
+        uses: actions/github-script@v7
+        with:
+          script: |
+            github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.pull_request.number,
+              body: `Thanks for opening this pull request.
+              I’ve received it and will review the changes shortly.'
+            });