Revise the revisions

[JJ]

And produce a second edition, three years after. There are some revise marks here and there. Check them out, or at least delete them.

[aprilyou]

Hello! I am a beginner at working with open source projects, and I am interested in this project. Are there more specific instructions for this issue?

Thank you very much! :)

[JJ]

There are several comments, like this along the text. Many sentences might have grammar errors. It would help if some native speaker would point them out and/or fix them.