Add auto generated HTML pages

[paypur]

I think I'm pretty close to being done, so here's what I have. There's definitely even more that can be done, like the tooltips we talked about, but that will have to be for later.

Preview: https://paypur.github.io/docs/books/1.20/
Tinkers' PR: SlimeKnights/TinkersConstruct#5456
Mantle PR: SlimeKnights/Mantle#231

Notes

• Every PageContent needs to override toHTML
• The auto-generated HTML is not very readable but I'm not sure if you care because you shouldn't manually edit it
• Exporting HTML piggybacks off of the /mantle book export but can be split into its own command
• Text is not exported in the images any more
• CSS is written assuming scale = 2, but this should be easy to change
• The old images are still there for comparing
• Loading images needs to download quite a lot of data (the encyclopedia is at 7MB if I remove the duplicated images, but image compression should help a lot)
• The book "chapters" feel kinda redundant now that we can just link to a specific page on an image
• Non Tinker's books might need to be updated to work with this

Still TODOs

• Fix ContentListings overflowing
• Compress the .png's
• Remove unnecessary HTML?? (like newlines)
• Remove old images (at least for 1.20.1)
• Add back the previous page layout for old versions
• Fix issues on mobile
• Rebase before we merge

[KnightMiner]

Something important to note: I don't want to replace the existing picture based books with HTML ones. I would rather have both. The reason is the image ones are way more likely to be stable on the chance the HTML updater breaks in the future, and are way more likely to be accurate across devices.

You will likely want a separate home page for HTML books vs image books, with links between the two as relevant.

[paypur]

Would it be better for the HTML books to be the primary, and the image books to be the fallback in case of any issues?

[KnightMiner]

Neither is really primary or fallback. They are just different pages. The book index can link them both:

Icon
Title
HTML / Images

Key thing is I want to have both. I find images works very nicely on mobile notably.

[paypur]

Ok so I put back the image books and separated the HTML book pages, theres just one more issue with fluid effects I need to fix