Add deploy step only on main branch

.github/workflows/deploy.yml

@@ -0,0 +1,37 @@
+name: Deploying to GH Pages 
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                node-version: [16.x]
+
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v2
+              with:
+                  fetch-depth: 2
+
+            - name: Set up Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v1
+              with:
+                  node-version: ${{ matrix.node-version }}
+
+            - name: Install dependencies
+              run: npm install
+
+            - name: Run tests
+              run: npm run test -- --coverage --watchAll=false
+
+            - name: Deploy 🚀
+              uses: JamesIves/github-pages-deploy-action@releases/v3
+              with:
+                  BRANCH: gh-pages
+                  FOLDER: build