See full step by step tutorial on Medium.
[1] Jekyll theme "Minimal" for GitHub Pages: https://github.com/pages-themes/minimal (CC0 1.0 Universal License)
[2] Dummy photo via: https://pixabay.com/photos/man-male-adult-person-caucasian-1209494/ (Pixabay License)
[3] Dummy thumbnail image created by rawpixel.com: https://www.freepik.com/free-vector/set-elements-infographic_2807573.htm (Standard Freepik License)