Temp fix until docsifyjs#704 gets fixed:

In order to use, just build then pack the dependency:
```
npm run build
npm pack packages/docsify-server-renderer/
```

src/core/router/history/abstract.js

@@ -7,7 +7,7 @@ export class AbstractHistory extends History {
     this.mode = 'abstract'
   }
 
-  parse(path) {
+  parse(path = '') {
     let query = ''
 
     const queryIndex = path.indexOf('?')