GitHub Actions: add lint

Author: kaloudis

.github/workflows/lint.yml

@@ -0,0 +1,13 @@
+name: Lint
+on: [push]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: '12.x'
+      - run: npm ci
+      - run: npm run lint