Rewrite Repo to conform to a lesscss file; hyper dynamic build steps

[coldenate]

👋 Hi there!

This pull request converts the CSS to LESS and allows for a build step to build all the palettes.

Why?

I saw the userstyles switching to LESS, and I appreciated the features less CSS has to offer. Since RemNote relies on its own internal dynamic appearance classes, it made development safer from me running find and replaces all over the repo to treat the small niches between all four flavours.

What does this do now?

The build step automatically handles the following

• determining all manifest.json parameters other than permissions and versioning.
• import all the proper palettes required to build the less css
• construct missing values in the imported file
• build the less CSS
• prepare and zip the individual theme folders for uploading to RemNote

What will happen next

I probably imagine tackling #12, but the main thing is a Plugin for RemNote. It will bare the exact same functionality as VSCode's catppuccin plugin which allows the user to customize their accent color and theme with the command palette. Accent colors are missing from this port, and their introduction is not possible with RemNote's current theming.

Now that I think about it, I will raise this as a feature request to RemNote dev team :)

Okay that's all. Bye!

[coldenate]

merged due to resolve changes. this is my first time doing a real pr with suggested changes, so let me know if need to revert and restore.