Add GitHub workflow

.github/workflows/build.yml

@@ -0,0 +1,75 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    outputs:
+      coverage: ${{ steps.coverage.outputs.value }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup Node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 18
+
+      - name: Install
+        run: npm ci
+
+      - name: Test and Coverage
+        run: npm run coverage
+
+      - name: Parse coverage
+        uses: sergeysova/jq-action@v2
+        id: coverage
+        with:
+          cmd: 'jq .total.statements.pct coverage/coverage-summary.json'
+
+      - name: Build demo
+        run: npm run build:demo
+
+      - name: Upload demo artifact
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: ./docs
+
+  badge:
+    runs-on: ubuntu-latest
+    needs: build
+
+    steps:
+      - name: Create badge
+        uses: schneegans/dynamic-badges-action@v1.6.0
+        with:
+          auth: ${{ secrets.GIST_SECRET }}
+          gistID: 7f2a04de5e494f9a3820832520ee2562
+          filename: badge.json
+          label: Code Coverage
+          message: ${{ needs.build.outputs.coverage }}%
+          valColorRange: ${{ needs.build.outputs.coverage }}
+          maxColorRange: 100
+          minColorRange: 0
+
+  deploy:
+    runs-on: ubuntu-latest
+    needs: build
+
+    permissions:
+      pages: write      # to deploy to Pages
+      id-token: write   # to verify the deployment originates from an appropriate source
+
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v1