anchor.diff:  register. For example `"sy` will yank (`y` command) in the `s` register. `"sp`
   will paste from the `s` register.
   
  -While in insert mode or in a prompt, `ctrl-r` followed by a register name
  +While in insert mode or in a prompt, `<c-r>` followed by a register name
   (one character) inserts it.
   
  -For example, `ctrl-r` followed by " will insert the currently yanked text.
  -`ctrl-r` followed by 2 will insert the second capture group from the last regex
  +For example, `<c-r>` followed by " will insert the currently yanked text.
  +`<c-r>` followed by 2 will insert the second capture group from the last regex
   selection.
   
   Registers are lists, instead of simply text in order to interact well with
  
positive.code:  * `y`: yank selections
   * `p`: paste after current selection end
   * `P`: paste before current selection begin
   * `alt-p`: paste all after current selection end, and
              select each pasted string.
   * `alt-P`: paste all before current selection begin, and
              select each pasted string.
   * `R`: replace current selection with yanked text
  
   * `r`: replace each character with the next entered one
  
   * `alt-j`: join selected lines
   * `alt-J`: join selected lines and select spaces inserted
              in place of line breaks
   * `alt-m`: merge contiguous selections together (works across lines as well)
  
   * `>`: indent selected lines
   * `alt->`: indent selected lines, including empty lines
   * `<`: deindent selected lines
   * `alt-<`: deindent selected lines, do not remove incomplete
          indent (3 leading spaces when indent is 4)
  
   * `|`: pipe each selections through the given external filter program
          and replace the selection with it's output.
   * `alt-|`: pipe each selections through the given external filter program
          and ignore its output
  
   * `!`: insert command output before selection
  
negative.code: Menus
  ~~~~~
  
  When a menu is displayed, you can use `j`, `<c-n>` or `<tab>` to select the next
  entry, and `k`, `<c-p>` or `<shift-tab>` to select the previous one.
  
  Using the `/` key, you can enter some regex in order to restrict available choices
  to the matching ones.
  