enable linting via CI

.github/workflows/lint.yml

@@ -0,0 +1,19 @@
+name: Lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12
+          registry-url: https://registry.npmjs.org/
+      - run: npm ci
+      - run: npm run lint

package.json

@@ -4,7 +4,7 @@
   "description": "TypeScript definitions for MediaWiki JS interface",
   "types": "index.d.ts",
   "scripts": {
-    "dtslint": "npx dtslint --localTs node_modules/typescript/lib ."
+    "lint": "npx dtslint --localTs node_modules/typescript/lib ."
   },
   "repository": {
     "type": "git",