Add Zen UI + KOReader

[AnthonyGress]

Here's the source code for Zen UI, it aims to be a fully themed experience on top of KOReader giving users a simple, clean, and intuitive interface.

https://github.com/AnthonyGress/zen_ui.koplugin

The launcher also runs KOReader with --framework_stop for a better experience on Kindle

Btw, thanks for making this awesome package manager as well as all your other contributions to the Kindle Jailbreak scene. I appreciate your hard work

Side note: I had an idea while using this. If you are familiar with Cydia or other package managers for iOS jailbreaks, it might be cool to extend KindleForge to allow other sources to be added. This way people could host/manage their own repos of kindle tweaks in addition to this main source.

[penguins184]

For the 'cydia' idea, we are waiting on a fully fledged package manager from Hackerdude as a part of KindleModding, not KindleTweaks. Unfortunately, this project has been stalled for ages. The current state of KF installs aren't really ideal.

[penguins184]

As for this PR, we're not yet planning to add KOReader plugins due to the vast amount of appstore koplugins (maybe we could just add one of those?). We have considered it though. If anything, I might keep this PR open since I have a small UI library in progress and if I rewrite the KF UI a KOReader tab or sect would be easier to implement... 🤔 Possibly accompanied by a more traditional package manager, if possible