fix(x): fixed npm pkg entry

Author: dlhandsome

packages/x/package.json

@@ -2,7 +2,7 @@
   "name": "@wepy/x",
   "version": "2.0.1",
   "description": "Vuex in WePY",
-  "main": "index.js",
+  "main": "dist/index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },