Add prettier and run prettier command via lint-staged (#448)

.github/workflows/test-workflow.yml

@@ -59,3 +59,22 @@ jobs:
 
       - name: Test i18n packs integrity
         run: npm run test:i18n-packs
+
+  prettier:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Test with prettier
+        run: npm run test:prettier