The Startup Process
(In the below description, zsh looks for user startup files in the user's home
directory by default.
To make it look in another directory, set the parameter ZDOTDIR to where you'd
like zsh to look.)
When zsh starts up, the following files are read (in order):
1. First, read /etc/zshenv (If the RCS option is unset in this system file, all
other startup files are skipped.)
2. Next, read ~/.zshenv
3. Next, IF the shell is a login shell, read /etc/zprofile, followed by
~/.zprofile
4. Next, IF the shell is interactive, read /etc/zshrc, followed by ~/.zshrc
5. Finally, if the shell is a login shell, read /etc/zlogin, followed by
~/.zlogin
