fix(vi-mode)!: add back edit-command-line key binding as 'vv' (#9573)

BREAKING CHANGE: the key binding to open an editor to edit the command line has
been moved from being `v` (press v once) to being `vv` (press v twice). Now, the
action for `v` is the default `visual-mode`, as is in Vim.

Fixes #9573

plugins/vi-mode/README.md

@@ -60,6 +60,12 @@ NOTE: some of these key bindings are set by zsh by default when using a vi-mode
 - `/`      : Search backward in history
 - `n`      : Repeat the last `/`
 
+### Vim edition
+
+- `vv`     : Edit current command line in Vim
+
+NOTE: this used to be bound to `v`. That is now the default (`visual-mode`)
+
 ### Movement
 
 - `$`   : To the end of the line
@@ -99,9 +105,5 @@ NOTE: some of these key bindings are set by zsh by default when using a vi-mode
 - `C`           : Delete to the end of the line and start insert
 - `r{char}`     : Replace the character under the cursor with {char}
 - `R`           : Enter replace mode: Each character replaces existing one
-- `x`           : Delete [count] characters under and after the cursor
+- `x`           : Delete `count` characters under and after the cursor
-- `X`           : Delete [count] characters before the cursor
+- `X`           : Delete `count` characters before the cursor
-
-### Removed key bindings
-
-- `v`   : Edit current command line in Vim

plugins/vi-mode/vi-mode.plugin.zsh

@@ -64,6 +64,11 @@ zle -N zle-line-finish
 
 bindkey -v
 
+# allow vv to edit the command line (standard behaviour)
+autoload -Uz edit-command-line
+zle -N edit-command-line
+bindkey -M vicmd 'vv' edit-command-line
+
 # allow ctrl-p, ctrl-n for navigate history (standard behaviour)
 bindkey '^P' up-history
 bindkey '^N' down-history