Enable vi mode in command line with indicator for Normal/Insert mode

enable-vi-command-line.sh

# Indicate whether user is in Normal / Insert mode
function zle-line-init zle-keymap-select {
   VIM_PROMPT="%{$fg_bold[yellow]%} [% NORMAL]%  %{$reset_color%}"
   RPS1="${${KEYMAP/vicmd/$VIM_PROMPT}/(main|viins)/} $EPS1"
   zle reset-prompt
 }

 set -o vi

 zle -N zle-line-init
 zle -N zle-keymap-select
# Increase the switching time between insert and normal mode in vim
 autoload edit-command-line
 zle -N edit-command-line
 bindkey -M vicmd v edit-command-line