anchor.diff:  View commands
   ~~~~~~~~~~~~~
   
  -Some commands, all begining with v permit to manipulate the current
  +Some commands, all beginning with v permit to manipulate the current
   view.
   
    * `vv` or `vc`: center the main selection in the window
  
positive.code: selections.
  
  Yanking and pasting uses the register `"`, however most commands using a register
  can have their default register overriden by using the `"` key followed by the
  register. For example `"sy` will yank (`y` command) in the `s` register. `"sp`
  will paste from the `s` register.
  
  
negative.code:  * `-shell-completion`: following string is a shell command which takes
      parameters as positional params and output one completion candidate
      per line.
   * `-allow-override`: allow the new command to replace an existing one
      with the same name.
   * `-hidden`: do not show the command in command name completions
   * `-docstring`: define the documentation string for the command
  