Add new workflow to prevent updating users.yml

.github/workflows/prevent-updating-users-yml.yml

@@ -0,0 +1,19 @@
+name: Prevent updating users.yml
+
+on:
+  pull_request:
+    paths:
+      - "website/data/users.yml"
+
+jobs:
+  prevent-add-users:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Create comment
+        uses: actions-ecosystem/action-create-comment@v1
+        with:
+          github_token: ${{ github.token }}
+          body: |
+            Thank you for using Prettier! But we don't accept updating `users.yml` anymore.
+            If you created this PR for a purpose other than adding users, please ping a maintainer.

website/data/users.yml

@@ -260,3 +260,6 @@
 - caption: Dev IT jobs
   image: /images/users/dev-it-jobs-200-100.jpg
   infoLink: https://devitjobs.uk
+- caption: Foo
+  image: /images/users/foo.jpg
+  infoLink: https://example.com