Update Catppuccin theme

[antoineco]

The theme now ships in 4 variants: frappe, latte, macchiato, and mocha; each with a different contrast.

This PR simply copies the conf files from upstream, without any modification.

Refs.

• https://github.com/catppuccin/kitty
• https://github.com/catppuccin/catppuccin/tree/main/docs