[Feature Request] Add theme suited for greyscale e-readers

[kpervin]

Describe your suggested feature

Buttons should be outline buttons instead of filled color, and the colour scheme should be exclusively black and white.

Other details

Using a Boox Page, the current offering of themes tend to favor color displays with a higher PPI. As such, filled display elements can result in lack of contrast, especially filled buttons with text inside them. It would be wonderful if there was an e-reader focused theme option that tailors the UI to be as legible as possible on a greyscale e-reader.

Acknowledgements

• [X] I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.
• [X] I have written a short but informative title.
• [ ] If this is an request for a feature in the original Tachiyomi, I am opening because multiple versions of TachiyomiJ2K have been released without this feature.
• [ ] If this is an issue with an extension, or a request for an extension, I should be opening an issue in the extensions repository.
• [X] I have updated the app to version 1.7.1.
• [X] I have checked through the app settings for my feature.
• [ ] I have admitted that I am a clown by having checked this box, as I have not read these acknowledgements.
• [X] I will fill out all of the requested information in this form.