Fish or Fish-shell is command line shell ready to go just after install with little configuration needed.
The main issue with fish is that it can break bash scripts so make sure to run scripts always on bash
fish_update_completions will read man mages for what you have installed and then use that for autocompletion. Just make sure
$MANPATH is set correctly
fish_config will open the webGUI to configure fish.
Make sure you follow these instruction