feat: support the command of auto-start script for shell

[jaeheonji]

This PR resolve #1109

Background

there was a need from people who wished to use zellij as the basis at the start of the shell. like #1091, #1268, #1273
The document already provides content related to this, but it does not seem to give people a consistent experience.

Therefore, providing settings through the CLI, such as #1109 and #1091, is considered a very good idea.

This is still a draft, but it will provide a variety of shell scripts. (bash, zsh, fish, etc)
Also, please let me know if you have any useful features to include in the script.

example in fish:

if status is-interactive
    ...

    # setup auto-start
    zellij setup --generate-auto-start fish | source
end