feat: add ANSI colours

[sgoudham]

This PR overhauls our ANSI colours by separating the "normals" and the "brights", note that this doesn't solve the readability issue raised in catppuccin/catppuccin#1961 as that will require more thought and analysis.

By landing this PR first, we can get the infrastructure in for easy updates to all of our terminal ports as the chain of updates are as follows: palette.json -> catppuccin/rust -> catppuccin/whiskers -> updates in all terminal whiskers templates.

For the colours themselves, we're adjusting the lightness, chroma and hue. Credit to @unseen-ninja for originally mocking up the jsfiddle/CSS that this is based on. However, I believe we need to adjust the formula as the library used (color.js) here is outputting different hex codes than the original mockup.

Leaving this as draft until we're happy with the final results.

[unseen-ninja]

After a lot of back and forth over the past couple of months I'm pretty happy with the results here. c:

While this doesn't resolve all of the issues that initially sparked this while ANSI thing I still think that the right way is to adhere to the standard and use the colours people would expect instead of diverting from it to potentially fix issues that stem from the fact that Catppuccin's colours don't necessarily work with every ANSI-standard interface out there. Especially with how text should be coloured on accent-background.

[sgoudham]

Thanks for the approval. I'm happy to merge this after I update the README 👍

[backwardspy]

awesome