docs: Add documentation about AeroSpace.app CLI flags

[nikitabobko]

These flags should be documented

$ /Applications/AeroSpace.app/Contents/MacOS/AeroSpace -h
USAGE: /Applications/AeroSpace.app/Contents/MacOS/AeroSpace [<options>]

OPTIONS:
  -h, --help              Print help
  -v, --version           Print AeroSpace.app version
  --started-at-login      Make AeroSpace.app think that it is started at login
                          When AeroSpace.app starts at login it runs 'after-login-command' commands
  --config-path <path>    Config path. It will take priority over ~/.aerospace.toml
                          and ${XDG_CONFIG_HOME}/aerospace/aerospace.toml