ci: Add prettier style check to CI

Author: ondrejsika

.github/workflows/style.yaml

@@ -0,0 +1,12 @@
+name: Style Check
+on: [push]
+jobs:
+  prettier:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: "17"
+      - run: yarn
+      - run: yarn run prettier-check