ci(lint): create a ci workflow

.github/workflows/lint.yml

@@ -0,0 +1,22 @@
+name: Lint
+
+on: pull_request
+
+jobs:
+  code:
+    name: Lint code
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Use Node.js 12
+        uses: actions/setup-node@v1
+        with:
+          node-version: "12"
+
+      - name: Install dependencies
+        uses: bahmutov/npm-install@v1
+
+      - name: Run ESLint
+        run: npm run lint