Add compatibility with most Zsh plugin managers

[jletey]

Feature Request

It's definitely a nice feature to have compatibility with most Zsh plugin managers, so that people don't have to adapt to either a new shell or plugin manager to just use our prompt.

Is your feature request related to a problem? Please describe.

I currently can't install this prompt using antibody, my preferred Zsh plugin manager.

Describe the solution you'd like

A one line to install the Starship prompt with my favoured plugin manager (I'm taking inspiration from the pure prompt).

Describe alternatives you've considered

[matchai]

As part of the discussion taking place in #47, there are solutions that would be plugin manager agnostic, so we shouldn't need to do anything special until we want to implement plugin manager specific installation.

[jletey]

Thanks for explaining, I'm going to go ahead and close this