To publish a GitHub page under the root domain of your
github.io username, you should set up a repository named
username.github.io, and it will take care of it.
Besides that, any other repository you create and set to publish pages, will be available at
An example of such repo: square/square.github.io.
If you want to have your repo (also?) under
steem-tutorials you can mirror that repo to
username.github.io. It will be both clearer from the name of the repo what it is, and will be easier to change your main site later, since it's not your actual repo.
• Read more at Getting Started with GitHub Pages