If you are going to add custom domains on your GitHub pages or maybe use a custom domain on your Github Hosted Jekyll Website then this tutorial is for you.
Read How to Make a Jekyll Blog With GitHub Pages.
First Go to Your repository and click on settings.
Now Scroll Down to git hub pages section.
Now Click on save.
Now go to your domain registrars website and find DNS setting. here you need to create 4 different records.
– A record for @ pointing to 185.199.108.153
– A record for @ pointing to 185.199.109.153
– A record for @ pointing to 185.199.110.153
– A record for @ pointing to 185.199.111.153
– CNAME record for www pointing to your username.github.io (the username should be replaced with your actual GitHub account username):
Wait for some time so that all changes take places. After some time you can access your access your repository on your perfect domain name.