Add optional prompt prefix if root

[pmccarren]

I propose we add an optional prefix to the prompt if we are root. I find the extra visibility to be of value when working on remote boxes in production.

The proposed prefix is adding a red #.
e.g. # ❯

We should default to hiding the prefix unless configured to do otherwise. This is accomplished by checking for the existence of the PURE_ROOT_HASH variable, which is by default not set.

[mafredri]

I don't think this is a common enough use case, and it wouldn't feel right to introduce yet another option just to have multiple indications of the same thing (there's already the white root).

You can easily achieve the same thing by setting the prompt symbol in your .zshrc:

# Being thorough here and closing the original %F{magenta} and not adding a %f at the end as this will be added by PS1
PURE_PROMPT_SYMBOL='%f%F{red}#%f %F{magenta}❯'

Does that work for you?

[mafredri]

This has been added to the readme: Prefix prompt when logged in as root. Even though this didn't turn out to be a good fit for Pure, we appreciate your contribution :).