Move the Hitchhiker's guide to this repo

[MalinAhlberg]

Suggestion from team Yellow:
The Hitchhiker's guide to NBIS could be kept here, instead of in google docs. This would make it easier to find and maintain.

[kusalananda]

Suggestion from team Yellow:
The Hitchhiker's guide to NBIS could be kept here, instead of in google docs. This would make it easier to find and maintain.

Is this something that we still want to do? I could transform the document from a Google Document to a markup document and put it in the repository. However, the repository is public and the Hitchhiker document feels a bit too internal.

I'd like to have more input on this.