docs(sudo): document key binding change

plugins/sudo/README.md

 # sudo
 
-Easily prefix your current or previous commands with `sudo` by pressing <kbd>esc</kbd> twice
+Easily prefix your current or previous commands with `sudo` by pressing <kbd>esc</kbd> twice.
 
 To use it, add `sudo` to the plugins array in your zshrc file:
 
@@ -43,3 +43,17 @@ $ sudo rm some-system-file.txt
 Password:
 $
 ```
+
+## Key binding
+
+By default, the `sudo` plugin uses <kbd>Esc</kbd><kbd>Esc</kbd> as the trigger.
+If you want to change it, you can use the `bindkey` command to bind it to a different key:
+
+```sh
+bindkey -M emacs '<seq>' sudo-command-line
+bindkey -M vicmd '<seq>' sudo-command-line
+bindkey -M viins '<seq>' sudo-command-line
+```
+
+where `<seq>` is the sequence you want to use. You can find the keyboard sequence
+by running `cat` and pressing the keyboard combination you want to use.