ci: add new pr comment workflow

.github/workflows/new-pr-comment.yml

@@ -0,0 +1,32 @@
+name: "New MR welcome comment"
+
+on:
+  pull_request:
+    types: [opened]
+
+jobs:
+  comment:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Add comment to PR
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const pr = context.payload.pull_request;
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: pr.number,
+              body: `Hello and thank you for making a PR to Hyprland!
+
+Please check the [PR Guidelines](https://wiki.hypr.land/Contributing-and-Debugging/PR-Guidelines/) and make sure your PR follows them.
+It will make the entire review process faster. :)
+
+If your code can be tested, please always add tests. See more [here](https://wiki.hypr.land/Contributing-and-Debugging/Tests/).
+
+_beep boop, I'm just a bot. A real human will review your PR soon._`
+            });