fix(package): correct 'types' of package

Author: jdbruijn

package.json

@@ -3,7 +3,7 @@
   "version": "1.1.8",
   "description": "commitlint plugin to define rules as functions.",
   "main": "dist/src/index.js",
-  "types": "dist/src/index.d.js",
+  "types": "dist/src/index.d.ts",
   "files": [
     "dist/src/**/!(*.test).{js,d.ts}"
   ],