add workflow actions for GitHub Pages deployment

.github/workflows/main.yml

@@ -0,0 +1,55 @@
+# https://github.com/actions/deploy-pages#usage
+name: Deploy to GitHub Pages
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    environment: github_pages
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - run: corepack enable
+      - uses: actions/setup-node@v3
+        with:
+          node-version: "18"
+
+      # Pick your own package manager and build script
+      - run: npm install
+      - run: npm run build
+        env:
+          NUXT_APP_BASE_URL: ${{ vars.NUXT_APP_BASE_URL }}
+          API_BASE_URL: ${{ vars.API_BASE_URL }}
+          EXTERNAL_API_KEY: ${{ secrets.EXTERNAL_API_KEY }}
+          NITRO_PRESET: github_pages
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: ./.output/public
+
+  # Deployment job
+  deploy:
+    # Add a dependency to the build job
+    needs: build
+
+    # Grant GITHUB_TOKEN the permissions required to make a Pages deployment
+    permissions:
+      pages: write      # to deploy to Pages
+      id-token: write   # to verify the deployment originates from an appropriate source
+
+    # Deploy to the github_pages environment
+    environment:
+      name: github_pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    # Specify runner + deployment step
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v1