Installation is partially manual, because I don't need it to install it very often and I need it working on multiple environments with different OSes. Auto-installation just doesn't worth the effort.
Use shell/.zshrc as an example, or just copy it, requires having oh-my-zsh installed.
I use built-in settings sync feature, this repo used as a backup.
Settings -> General -> Import all settings & data -> select *.itermexport file