refactor(themes): adjust `catppuccin-latte` & add comments

[sgoudham]

Hey :wave:, this PR introduces some changes as part of merging https://github.com/catppuccin/zellij/pull/11 downstream.

We noticed that the fg and bg keys for catppuccin-latte were the same which seemed incorrect, however, we couldn't find any noticeable changes on the UI when changing these keys. Catppuccin Latte now (properly) uses surface2 for the background and text for the foreground, matching the other existing flavours. Furthermore, black is now mapped to mantle, also matching the other existing flavours.

I'd appreciate any insight into why Catppuccin Latte seemed to function well even with the foreground and background keys set to the same colour.

I've also added comments to map white and fg to the Catppuccin palette colour of text.

Hope these changes are fine and let me know if there's anything else I need to edit, thanks!

[imsnif]

Hey @sgoudham and @jaeheonji - I didn't notice this PR, and when working on some fixes for the new UI I also noticed this issue. I changed fg to #5c5f77 (Subtext 1) because it looked best to me. In our context it's mostly about adjusting the color of unselected ribbons. Here's an example of how it looks in the new UI:

What do you think?

Otherwise (maybe related, maybe not) I'm a little concerned about the contrast of the magenta and red variants (as can be seen in these screenshots with Ctrl g and <n> New Pane (the n part) respectively). Do you have any thoughts?

[jaeheonji]

Hey! Sorry for late reply.

When I first added the catppuccin theme to zellij, I added it slightly differently from the catppuccin color rules. The reason is that because of some UI errors and unused colors that we had previously, I added the most appropriate color expression to zellij at that time.

In my opinion, I think it is fine to modify the color palette suitable for zellij as long as the look and feel of the theme matches. So, @imsnif I think that one looks good.