[Feature Request] Highlighting and annotation

[Sfuniversal]

Im pretty sure epub.js already have these in their api but if these were added it would improve user experience because we can save notes and remember certain things kinda like bookmarks

[iwtkn]

I would love to see this implemented, highlighting and annotation feature will make it a complete reader.

[WiseAppCo]

I try to add this using rangy and texthighlight.js but it returns error js not defined.