Maybe .github is a special repository that shows the readme for a Personal GitHub just like for GitHub Organization?
No, for Personal Github https://github.com/bestia-dev, the special repository for readme must have the name of the GitHub user_name: https://github.com/bestia-dev/bestia-dev.
Pretty inconsistent :-(
And for a quasi personal website https://bestia-dev.github.io/ the repository has to be named like https://github.com/bestia-dev/bestia-dev.github.io.
Of course, I redirected this quasi website to my true website https://bestia.dev.