add ts setting to package.json

package.json

   "version": "1.1.5",
   "description": "An auto height webview for React Native, even auto width for inline html",
   "main": "autoHeightWebView",
+  "types": "index.d.ts",
   "files": [
     "index.js",
+    "index.d.ts",
     "autoHeightWebView"
   ],
   "scripts": {