Add gruvchad theme extension

[notxorand]

Ported the Gruvchad theme from NvChad

[MrSubidubi]

Could you please look into the CI issues?

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Ubuntu.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[notxorand]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[notxorand]

@MrSubidubi it was due to the lack of a license. included one, so should be fixed

[MrSubidubi]

Thanks!