anchor.diff:   * +regex+: as a string but the +set+ commands will complain
      if the entered text is not a valid regex.
    * +{int,str}-list+: a list, elements are separated by a colon (:)
  -   if an element needs to contain a colon, it can be escaped with a
  +  if an element needs to contain a colon, it can be escaped with a
      backslash.
   
   Options value can be changed using the +set+ commands:
  
positive.code:  * +kak_hook_param+: filtering text passed to the currently executing hook
  
  Note that in order to make only needed information available, Kakoune needs
  to find the environement variable reference in the shell script executed.
  Hence +%sh{ ./script.sh }+ with +script.sh+ referencing an environement will
  not work.
  
  for example you can print informations on the current file in the status
  
negative.code: 
  def can also takes some flags:
  
   * +-env-params+: pass parameters given to commands in the environment as
                    kak_paramN with N the parameter number
   * +-shell-params+: pass parameters given to commands as positional parameters
                      to any shell expansions used in the command.
  