Add workflow to check formatting

Author: alexesprit

.github/workflows/format.yml

@@ -0,0 +1,24 @@
+name: Format
+on:
+  push:
+    branches: [master]
+  pull_request:
+    types: [opened, synchronize]
+jobs:
+  format:
+    name: Check formatting
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@v2
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v1
+        with:
+          node-version: '14'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Check formatting
+        run: npm run format:check