Merge pull request #73 from firebase/feat/add-tag-diff

feat: add tag diff action

Author: HYACCCINT

.github/workflows/tag-diff.yml

@@ -0,0 +1,15 @@
+name: Tag Diff
+
+on:
+  pull_request:
+    
+jobs:
+  tag-diff:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Git Checkout"
+        uses: actions/checkout@v2
+      - name: "Diff tags"
+        uses: invertase/quickstart-tag-differ@v0.0.2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}