firebase-hosting preview deploys

.github/workflows/deploy-preview.yml

@@ -0,0 +1,21 @@
+name: Deploy to Preview Channel
+
+on:
+  pull_request:
+    # Optionally configure to run only for specific files. For example:
+    # paths:
+    # - "website/**"
+
+jobs:
+  build_and_preview:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      # Add any build steps here. For example:
+      # - run: npm ci && npm run build
+      - uses: FirebaseExtended/action-hosting-deploy@v0
+        with:
+          repoToken: "${{ secrets.GITHUB_TOKEN }}"
+          firebaseServiceAccount: "${{ secrets.FIREBASE_SERVICE_ACCOUNT }}"
+          expires: 30d
+          projectId: tryrowy