zsh-autocomplete

Installation
1. Add at or near the top of your .zshrc file (before any calls to compdef):
  source $HOMEBREW_PREFIX/share/zsh-autocomplete/zsh-autocomplete.plugin.zsh
2. Remove any calls to compinit from your .zshrc file.
3. If you're using Ubuntu, add to your .zshenv file:
  skip_global_compinit=1
Then restart your shell.
For more details, see:
  https://github.com/marlonrichert/zsh-autocomplete