feature: add base16 support

[bloxx12]

Description

This PR aims to provide basic base16 support. This is more of a draft and by far not finished, there are several things to be improved still. base16 theming is working by now, what is to be fixed/redone:

• Loading of plugins like base16-nvim, at the moment theme.name = "base16-nvim" enables theming via base16, it'd be nice to just be able to use theme.name = "base16".
• definition of the 16 hexadecimal colors
• documentation updates
• improve code quality to a point where Dianimo does not get angry upon seeing it

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

Please try to check at least a majority of the checklist before opening your pull request. Exceptions to this will be reviewed on a case by case basis.

• My code follows the style and contributing guidelines of this project.
• I ran Alejandra to format my code (nix fmt).
• I have performed a self-review of my own code and tested it.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• This change requires a documentation update.
• I have updated the documentation accordingly.

[C4E5G3]

Hi Bloxx,

Is it Raf who has to review the additions?

[bloxx12]

Hey there, there is still stuff to be done so this will not be merged yet, I may end up redoing the whole theming module if I find the time, since it's kind of hard to implement base16 cleanly in the current one. I'm still working on this, stay tuned till the weekend! :)

[diniamo]

Please reopen this PR to target the v0.7 branch.

[NotAShelf]

I rebased the PR against 0.7. If there are any merge conflicts, GH UI should point them out.

[diniamo]

Didn't know that was possible

[diniamo]

You could include Closes #270 in the PR description

[NotAShelf]

I've just noticed, you're missing a changelog entry in /docs/release-notes/0.7.md If you add the entry, I think we'll be golden.

[C4E5G3]

Okay, but base16 is not yet in the supported themes

[NotAShelf]

Base16 support is officially in the v0.7 branch, which is not yet merged to stable (main). You can test v0.7 by pinning it as your input, or you can wait until 0.7 is merged into main.

[C4E5G3]

I tried pinning v.7 but this change

• Removed input 'nvf/plugin-cmp-luasnip'
• Added input 'nvf/plugin-cmp-vsnip':

means my vim.autocomplete settings no longer work:

  error: The option `vim.autocomplete.sources' does not exist. Definition values:
┃        - In `<unknown-file>':
┃            {
┃              buffer = "[Buffer]";
┃              nvim_lsp = "[LSP]";
┃              path = "[Path]";
┃            }

[NotAShelf]

The autocompletion module was reworked in #404

Please refer to the changelog entry for how to migrate.