[v1.31.2] Photon theming changes, new markdown renderer, and lots of tweaks

There was like 8 prereleases for this because i kept changing stuff. This is actually going to be from v1.31.1 and v1.31.2.

Biggest changes

Command palette

• 
• Press / or ctrl + p and start typing to instantly go to a page, switch themes, switch accounts, etc.

Theming changes

• You can now have multiple presets for themes, and there are 5 default presets. (Default, Classic, AMOLED, Catppuccin, Lightly)
• Admins can set their own default theme for photon with PUBLIC_THEME.

New markdown renderer

• Photon now uses svelte-markdown for markdown rendering, which lets me use custom components for markdown.
• Instead of only style changes, I can run actual code, meaning images can be made expandable and codeblocks can be copyable.

Lots of languages

• There are a ton of languages thanks to the community.
• English
• Hebrew
• Bulgarian
• Chinese
• Dutch
• Estonian
• Finnish
• French
• German
• Japanese
• Polish
• Portuguese

Minor features

• New "link actions" menu
  • This will have options for archive sites to bypass paywalls, etc.
  • Media bias action was moved next to here, or in here depending on your selected post style.
• Allow uploading multiple images at a time
• Select menus use my own components now, making them more powerful
• Add infinite scroll to communities too
• Add uploaded media/voted posts in your profile page
• Using my own service worker now, so caches should work properly

Other stuff

• Use sharper icons for readability