added high contrast themes for zed

[rakshit087]

Adds 10 high contrast theme variants of popular dark themes for Zed — designed for maximum readability and reduced eye strain.

Theme	Base
High Contrast Ayu	Ayu
High Contrast VSCode	VSCode Dark+
High Contrast One Dark	One Dark
High Contrast Catppuccin Mocha	Catppuccin Mocha
High Contrast Gruvbox	Gruvbox
High Contrast Tokyo Night	Tokyo Night
High Contrast Dracula	Dracula
High Contrast Nord	Nord
High Contrast Monokai	Monokai
High Contrast Solarized Dark	Solarized