Fixed typo in file list

Author: andreas-aeschlimann

package.json

@@ -46,7 +46,7 @@
     "src/json2typescript/*.map",
     "src/json2typescript/*.js",
     "index.d.ts",
-    "index.map",
+    "index.js.map",
     "index.js"
   ],
   "repository": {