Add type path. (#476)

加上类型路径，不然有些编辑器提供不了类型提示

Author: mushan0x0

package.json

@@ -20,6 +20,7 @@
   ],
   "main": "./lib/index",
   "module": "./es/index",
+  "types": "./lib/index.d.ts",
   "homepage": "http://github.com/react-component/table",
   "maintainers": [
     "[email protected]",