feat: added light version for vercel zsh theme

[ataricoder]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Feature: Added a light mode version for Vercel's zsh theme.

What is the current behavior? (You can also link to an open issue here)

For users with light mode terminals, the current Vercel zsh theme does not play well.

What is the new behavior (if this is a feature change)?

Changed prompts color from white to black to allow for visibility in light mode terminals

Additional info:

Instead of manually installing and configuring oh-my-zsh to edit Vercel's zsh theme, this would allow for easy plugin installation via the Fig plugin store. I think what Fig is doing is awesome, and reduces the headache of maintaining local dot files