How can i overwrite parse rule js?

now it impossible,cause

```
https://github.com/unmantained-activeadmin-plugins/activeadmin-wysihtml5/blob/master/app/assets/javascripts/activeadmin-wysihtml5/base.js.coffee#L2

https://github.com/unmantained-activeadmin-plugins/activeadmin-wysihtml5/blob/master/lib/active_admin/wysihtml5/rails/engine.rb#L18
```

can we split js and include rules manually? 
