A reference for me:

https://annimon.com/article/2658

https://jekyllrb.com/docs/posts/
https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet
https://help.github.com/articles/using-jekyll-as-a-static-site-generator-with-github-pages/


Tutorials:

https://frontender.info/build-blog-jekyll-github-pages/