The tutorial is available in two languages as of now.
You are currently on the master branch. The contents is available at per-language branches.
Please switch to en branch for the English version: https://github.com/iliakan/javascript-tutorial/tree/en.
Учебник JavaScript на русском языке находится в ветке ru: https://github.com/iliakan/javascript-tutorial/tree/ru.