Add lint Github Action

.github/workflows/lint.yml

@@ -0,0 +1,16 @@
+name: Lint
+on: [push, pull_request]
+defaults:
+  run:
+    working-directory: ./admin
+jobs:
+  lint-admin:
+    runs-on: ubuntu-latest
+    name: Admin (Next.js)
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: "16"
+      - run: yarn install
+      - run: yarn run lint