Adding Catppuccin themes

Hi, this is my first contribution to KDE, so I apologize if I messed something up.

Catppuccin is a very popular MIT licenced colour scheme with four variants (latte, frappé, macchiato and mocha). I've tried to make a ksyntax theme for it, following catppuccin's style guide, and it's on the catppuccin org now (images attached). I would love to see this merged to be included by default.