feat(theme): add "forest" (@28Zapper)

[28Zapper]

Description

Checks

• Adding quotes?
  • Make sure to include translations for the quotes in the description (or another comment) so we can verify their content.
• Adding a language?
  • Make sure to follow the languages documentation
  • Add language to packages/schemas/src/languages.ts
  • Add language to exactly one group in frontend/src/ts/constants/languages.ts
  • Add language json file to frontend/static/languages
• Adding a theme?
  • Make sure to follow the themes documentation
  • Add theme to packages/schemas/src/themes.ts
  • Add theme to frontend/src/ts/constants/themes.ts
  • Add theme css file to frontend/static/themes
  • Add some screenshot of the theme, especially with different test settings (colorful, flip colors) to your pull request
• Adding a layout?
  • Make sure to follow the layouts documentation
  • Add layout to packages/schemas/src/layouts.ts
  • Add layout json file to frontend/static/layouts
• Adding a font?
  • Make sure to follow the themes documentation
  • Add font file to frontend/static/webfonts
  • Add font to packages/schemas/src/fonts.ts
  • Add font to frontend/src/ts/constants/fonts.ts
• Check if any open issues are related to this PR; if so, be sure to tag them below.
• Make sure the PR title follows the Conventional Commits standard. (https://www.conventionalcommits.org for more info)
• Make sure to include your GitHub username prefixed with @ inside parentheses at the end of the PR title.

Closes

[28Zapper]

I followed all of the guidelines accordingly and "Prettier Check" STILL doesn't want to work >:'(
Why. I didn't do some out of left field things to the files so I don't understand why it keeps failing :(((

[Leonabcd123]

Pretty similar to the color schema in matcha moccha.

[28Zapper]

I mean I get where you’re coming from but it’s a lot darker and more comglfy for the eyes (imo). It’s similar but not to the point where you can’t differentiate them at a glance