Adds workflow file to check for labels on PRs

.github/workflows/check-pr-label.yml

@@ -0,0 +1,18 @@
+name: 
+
+on: [pull-request]
+
+jobs:
+  check-for-label:
+    runs-on: ubuntu-latest    
+    steps:
+    - name: Labels not added
+      if: >
+        contains(github.event.pull_request.labels.*.name, 'Breaking-Changes') == false &&
+        contains(github.event.pull_request.labels.*.name, 'Bug-Fixes') == false &&
+        contains(github.event.pull_request.labels.*.name, 'Documentation') == false &&
+        contains(github.event.pull_request.labels.*.name, 'Feature') == false &&
+        contains(github.event.pull_request.labels.*.name, 'Chore') == false
+      run: |
+        echo "This PR can't be merged, because it does not have a release category label. See release_notes.md"
+        exit 1