The only viable way I found to bring Gitbook content within the main project website (i.e. https://myproject.com/docs) is ripping the Gitbook HTML content with wget

 wget -p -r -l10 -E -k -nH "https://my-gitbook-project"

And later host it as static pages.

The resulting HTML may need some tweaks.

Drawbacks

• If you have content in multiple branches in multiple "spaces", then the branch selector will need to be replaced.

• Even after wget, it's still a client-rendered ReactJS website, so SEO will be anyway inferior.

At the moment wget is the best workaround for Gitbook explicit refusal to implement subdirectory integration (i.e. myproject.com/docs, which is much better for SEO) as opposed to subdomain integration (i.e. docs.myproject.com).

Personally, I'm seriously considering migrating my documentation away from Gitbook at this point. Even if the two-way-sync with Github is very convenient.

I found out how to do it.

I created a BUTTON-COLOR.md file.

In the file I needed this line:

{% include "git+https://github.com/blah/button-color.git/README.md" %}

In SUMMARY.md i Just added the reference to BUTTON-COLOR.md:

# Summary

* Introduction

* button-color