message: _cargo: Explain how _cargo_cmds works
diff: @@ -422,6 +422,17 @@ _cargo() {
  _cargo_cmds() {
  local -a commands
  + # This uses Parameter Expansion Flags, which is an Zsh built-in features.
  + # See more: http://zsh.sourceforge.net/Doc/Release/Expansion.html#Parameter-Expansion-Flags
  + # and http://zsh.sourceforge.net/Doc/Release/Expansion.html#Parameter-Expansion
  + #
  + # # How this work?
  + #
  + # First it splits the result of `cargo --list` at newline, then it removes the first line.
  + # Then it removes indentation (4 whitespaces) before each items. (Note the x## pattern [1]).
  + # Then it replaces those spaces between item and description with a `:`
  + #
  + # [1]: https://github.com/zsh-users/zsh-completions/blob/master/zsh-completions-howto.org#patterns
  commands=( ${${${(M)"${(f)$(cargo --list)}":# *}/ ##/}/ ##/:} )
  _describe 'command' commands
  }
  