chore(dist): fix npm script 'postinstall'

Author: phphe

package.json

@@ -1,13 +1,14 @@
 {
   "name": "he-tree-vue",
-  "version": "2.0.7-beta.1",
+  "version": "2.0.7-beta.2",
   "description": "A draggable sortable nested vue tree component.",
   "main": "dist/he-tree-vue.cjs.js",
   "module": "dist/he-tree-vue.esm.js",
   "types": "types/index.d.ts",
   "files": [
     "dist",
-    "types"
+    "types",
+    "npm-scripts"
   ],
   "unpkg": "dist/he-tree-vue.js",
   "author": "phphe <phphe@outlook.com> (https://github.com/phphe)",