feat(lang): add nushell language support

[hustcer]

Try to add nushell language support

[the-mikedavis]

To clear up the ❌ from the Docs CI you'll need to run cargo xtask docgen and commit the results

[hustcer]

To clear up the ❌ from the Docs CI you'll need to run cargo xtask docgen and commit the results

Thanks, updated

[the-mikedavis]

A few small changes but this is looking good so far 👍

[hustcer]

Thanks, all fixed

[the-mikedavis]

looks good, thanks for working on this!