Custom `agnoster` path - display last dir in the current path

agnoster-prompt-dir.sh

# Path to file
# .oh-my-zsh/themes/agnoster.zsh-theme

# Dir: current working directory
prompt_dir() {
  # Default
  # Display the full path
  # prompt_segment blue $CURRENT_FG '%~'

  # Custom
  # Zsh expansion that truncates the path to just the last directory in the current path.
  # Thanks, chatgippitty :)
  prompt_segment blue $CURRENT_FG '%1~'
}