Add types to package.json

Author: wooorm

package.json

@@ -26,7 +26,9 @@
   "contributors": [
     "Titus Wormer <[email protected]> (https://wooorm.com)"
   ],
+  "types": "types/index.d.ts",
   "files": [
+    "types",
     "index.js"
   ],
   "dependencies": {