Fix `zinit` issue

[nathanshelly]

This line:

https://github.com/nathanshelly/.files/blob/2978a9c128fdbf5fafc34eb115013c8fc8ae9067/zsh/plugins.zsh#L50

causes the following output on every new shell creation:

(eval):1: ZPLGM: assignment to invalid subscript range

[lugoues]

Since you are one of the few google results when looking for this error. The fix is to use ZINIT instead of ZPLGM. :) https://github.com/zdharma/zinit/blob/master/CHANGELOG.md#L15

[nathanshelly]

thanks @Lugoues!