New action Pull Request Reminder (#283)

.github/workflows/pr-reminder.yml

@@ -0,0 +1,19 @@
+name: Pull Request Reminder
+
+on:
+  pull_request_target:
+    types:
+      - labeled
+
+jobs:
+  reminder:
+    if: ${{ github.event.label.name == 'Configurations' }}
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Comment PR
+      uses: marocchino/sticky-pull-request-comment@v2
+      with:
+        message: |
+          This pull request contains changes to the configuration file. Please make sure the documentation in [NexT website](https://theme-next.js.org/docs/) is changed or added.
+          Please edit relevant source files here: https://github.com/next-theme/theme-next-docs/tree/master/source/docs and create a pull request with the changes here: https://github.com/next-theme/theme-next-docs/pulls