refactor: ignore explicit index file reference

Author: jamesgeorge007

lib/commands/start.js

@@ -3,7 +3,7 @@
 const connect = require('connect')
 const serveStatic = require('serve-static')
 const Renderer = require('docsify-server-renderer')
-const util = require('../util/index')
+const util = require('../util')
 const chalk = require('chalk')
 const LRU = require('lru-cache')