installer: add option to not run zsh at the end
installer: add option to not run zsh at the end

Co-authored-by: Liquidsoul <f11b12823e1ba0e4253145441b0255e438af4077@liquidsoul.fr>
Co-authored-by: Alexander Polynomdivision <a60fa179745852ea286e96857df152439f9dd13f@googlemail.com>
Co-authored-by: loket <aff54fad763c81dc90624fcf0ebe6934d6f8230e@cruftlab.io>
Co-authored-by: Connor Demille <2d547390178a6a81d62e2c636bee8ddbd2dc8e78@gmail.com>

tekniklr/oh-my-zsh,tekniklr/oh-my-zsh