Add cursor shape change dependant on vi mode

README.md

@@ -84,6 +84,21 @@ and multi-terminal history support is enabled.
 The vi mode line editor is enabled. [zsh-vim-mode][vim-mode] was a reasonable
 starting point but was replaced as it uses some strange defaults.
 
+#### Cursor Shape
+
+In order to easily ascertain which vi mode the line editor is currently using
+escape sequences are sent to the terminal emulator on certain events to change
+the current shape of the cursor. Two cursor shapes are used; block for `vicmd`
+mode; a vertical line for `viins` mode. Additional escape sequences are used
+when [tmux][tmux] is detected to ensure the terminal emulator receives the
+appropriate sequence. [iTerm2][iterm2] and VTE compatible terminal emulators are
+supported.
+
+Three hooks are registered with the line editor; `zle-keymap-select` changes the
+cursor shape then the mode is changed; `zle-line-init` changes the shape
+starting editing a new command; and `zle-line-finish` resets the cursor shape
+when the line edit is complete.
+
 #### `vicmd` Mode
 
 Undo and repo and enabled using `u` and `U`. Showing help for the command under
@@ -127,4 +142,6 @@ Various aliases are defined at the end of [zshrc](zshrc) for convenience.
 [syntax]: https://github.com/zsh-users/zsh-syntax-highlighting
 [search]: https://github.com/zsh-users/zsh-history-substring-search
 [vim-mode]: https://github.com/sharat87/zsh-vim-mode
+[tmux]: https://tmux.github.io
+[iterm2]: https://www.iterm2.com
 [vim]: http://www.vim.org/