Add boxnovel.art to LightNovelWorldParser.js

[rizkiv1]

It's same theme/site with novelfire.net. Example https://boxnovel.art/book/horror-game-developer-my-games-arent-that-scary/chapters and https://novelfire.net/book/horror-game-developer-my-games-arent-that-scary/chapters.

[dteviot]

@rizkiv1

Thank you @nothing0074

Test versions for Firefox and Chrome have been uploaded to https://github.com/dteviot/WebToEpub/releases/tag/developer-build. Pick the one suitable for you, follow the "How to install from Source (for people who are not developers)" instructions at https://github.com/dteviot/WebToEpub/tree/ExperimentalTabMode#user-content-installation and let us know how it goes.