How to simplify github pages rendering?

Question

GitHub

Here is the ability to publish static pages on github, for this you need to create a separate repository called "username.github.io" and load the desired page into it, and if I have a layout in a separate repository, I have to copy-paste the repository to the repository to get link "username.github.io/repositoryname", how can I make it shorter without copy-paste? Here I found an acc, there is not this crutch repository for demonstrating the project from the repository, I also want it that way, how can I do it myself?
https://github.com/mauserkurz/alisayed