fix: add the lost npm files (#66)

ngot · fengmk2 · commit 495f1ab625d4 · 2018-07-31T11:35:16.000+08:00
diff --git a/package.json b/package.json
@@ -6,6 +6,7 @@
   "browser": "browser.js",
   "files": [
     "index.js",
+    "index.d.ts",
     "browser.js",
     "lib"
   ],
