ci: introduce staging deployment actions

.github/workflows/deploy-firebase-production.yml

@@ -0,0 +1,20 @@
+name: Deploy to Firebase (production)
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  deploy_live_website:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+
+      - name: Deploy to Firebase (production)
+        uses: FirebaseExtended/action-hosting-deploy@v0
+        with:
+          repoToken: '${{ secrets.GITHUB_TOKEN }}'
+          firebaseServiceAccount: '${{ secrets.FIREBASE_SERVICE_ACCOUNT_POSTWOMAN_API }}'
+          channelId: live
+          projectId: postwoman-api