The project is based on a library SaswatPadhi/pseudocode.js: Beautiful pseudocode for the Web (github.com). You can just use below packages in your LaTeX project and it will work:
\usepackage{algorithm,algpseudocode}
Be aware that all commands should look like \State instead of \STATE. But I just use all-capital in the demo, which would make the code not work in LaTeX. Good news is that the library is case-insensitive.
I will modified my demo and auto-completion within this week.