anchor.diff:      This highlights C++ style comments in cyan, with an eventual 'TODO:'
       in yellow on red background:
   
  --------------------------------------------------------------------
  -add-highlighter window regex //\h*(TODO:)[^\n]* 0:cyan 1:yellow,red
  --------------------------------------------------------------------
  +--------------------------------------------------------------------
  +add-highlighter window/ regex //\h*(TODO:)[^\n]* 0:cyan 1:yellow,red
  +--------------------------------------------------------------------
   
   *dynregex* <expression> <capture_id>:<face> ...::
       similar to regex, but expand (like a command parameter would) the
       given expression before building a regex from the result.
       This highlights all the current search matches in italic:
   
  -----------------------------------------------
  -add-highlighter window dynregex '%reg{/}' 0:+i
  -----------------------------------------------
  +-----------------------------------------------
  +add-highlighter window/ dynregex '%reg{/}' 0:+i
  +-----------------------------------------------
   
   == Specs highlighters
   
  
positive.code: can be added to an existing group or scope using:
  
  -----------------------------------
  add-highlighter <path> group <name>
  -----------------------------------
  
  That group is then accessible using the *<path>/<name>* path
  
  ------------------------------------------------
  add-highlighter <path>/<name> <type> <params>...
  ------------------------------------------------
  
  In order to specify which kinds of highlighters can be added to a given group, the *-passes*
  flag set can be passed along with the group name. Possible values for this option can be one
  or several (separated with a pipe sign) of *colorize*, *move* or *wrap* (default: *colorize*):
  
  --------------------------------------------------------------
  add-highlighter window group -passes colorize|move|wrap <name>
  --------------------------------------------------------------
  
  == Regions highlighters
  
negative.code: 
  It can then be referenced in a window using the ref highlighter.
  
  ----------------------------------
  add-highlighter window/ ref <name>
  ----------------------------------
  
  The ref can reference any named highlighter in the shared scope.
  