feat: setup firebase hosting for prod

.github/workflows/firebase-hosting-merge.yml

@@ -0,0 +1,19 @@
+# This file was auto-generated by the Firebase CLI
+# https://github.com/firebase/firebase-tools
+
+name: Deploy to Firebase Hosting on merge
+'on':
+  push:
+    branches:
+      - main
+jobs:
+  build_and_deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: FirebaseExtended/action-hosting-deploy@v0
+        with:
+          repoToken: '${{ secrets.GITHUB_TOKEN }}'
+          firebaseServiceAccount: '${{ secrets.FIREBASE_SERVICE_ACCOUNT_POSTWOMAN_API }}'
+          channelId: live
+          projectId: postwoman-api