Improve scripts, add TypeScript as dev dependency

Author: mxmason

package-lock.json

@@ -18,7 +18,7 @@
     "test:staged": "CI=true jest --findRelatedTests",
     "version": "auto-changelog -p --template keepachangelog && git add CHANGELOG.md",
     "prepublishOnly": "git push && git push --tags && gh-release",
-    "prepare": "husky install"
+    "prepare": "husky install && npm run build"
   },
   "keywords": [
     "netlify",
@@ -43,15 +43,18 @@
     "husky": "^7.0.0",
     "jest": "^27.3.1",
     "lint-staged": "^11.2.6",
-    "prettier": "^2.4.1"
+    "prettier": "^2.4.1",
+    "typescript": "^4.4.4"
   },
   "repository": "https://github.com/netlify-labs/netlify-plugin-a11y",
   "bugs": {
     "url": "https://github.com/netlify-labs/netlify-plugin-a11y/issues"
   },
   "lint-staged": {
+    "src/**/*.js": [
+      "npm run test:staged"
+    ],
     "*.js": [
-      "npm run test:staged",
       "eslint --cache --fix",
       "prettier --write"
     ]