I develop an iOS app and I comment my code in Doxygen style. I would use the feature "pages" proposed by GitHub but unfortunately, pages can't be private.
After searching on Google, I saw this POST – Private pages for a private Github repo
Regarding the Joel Glovier's answer, I can use Jekyll to create private pages on GitHub.
Can Jekyll manage Doxygen doc ?
Best Answer
According to GitHub Pages documentation:
All project repositories are ready to use the generator for publishing. However, please note that private repositories will publish pages that are public.
There is no way to create private GitHub pages, even from a private GitHub repository.
Source: https://help.github.com/articles/creating-pages-with-the-automatic-generator