ci: action to deploy to vercel

.github/workflows/vercel.yml

@@ -0,0 +1,21 @@
+# Deploy to Vercel action is created because the project is under an organization.
+# Vercel itself cannot link a project under an organization with hobby plan.
+
+name: Deploy Vercel
+on:
+  push:
+    branches: [ master ]
+  workflow_dispatch:
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          next build
+      - uses: amondnet/vercel-action@v25 #deploy
+        with:
+          vercel-token: ${{ secrets.VERCEL_TOKEN }} # Required
+          vercel-args: '--prod' #Optional
+          vercel-org-id: ${{ secrets.VERCEL_ORG_ID}}  #Required
+          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID}} #Required