Add suport to nushell

[AllanSiqueira]

Is your feature request related to a problem? Please describe. I will like have a script like there is for zsh and fish to nushell

Describe the solution you'd like

• [x] Create a nushell script that add the respecting env vars
• [x] Add the instructions on the README file

Describe alternatives you've considered I can create the script on my dotfiles, but I think will be great to have it for more people to use :)

Additional context N/A