Add workflow to check labels

Author: alcaeus

.github/workflows/check-labels.yml

@@ -0,0 +1,19 @@
+name: Label Checker
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - labeled
+      - unlabeled
+
+jobs:
+  check_labels:
+    name: Check labels
+    runs-on: ubuntu-latest
+    steps:
+      - uses: docker://agilepathway/pull-request-label-checker:latest
+        with:
+          one_of: bug,feature,enhancement,documentation,dependencies
+          repo_token: ${{ secrets.GITHUB_TOKEN }}