nushell support for shell-helpers

[b0lle]

Is your feature request related to a problem? Please describe.
It would be great to add nushell support for shell-helpers

Additional context
Nushell is a modern shell. aws-sso-cli could be a nice replacement for the oh-my-zsh aws plugin, which obviously does not work in nushell.

[synfinatic]

@b0lle: Lots of shells out there and while I'm sure nushell is awesome, I've honestly never heard of it which makes this a low priority for me. If someone provides a pull request to add the shell helper code, that would help a lot and dramatically improve the chances this happens.