FOSS gamedev and creative worlds

A lot of people are willing to contribute, but they don't know how to make a PR (like me). It would be nice if an expert can make a step by step tutorial how to make this, e.g. fork a project, make a clone to the PC, edit the code, merge the changes, create a PR

Take a look at http://dev.minetest.net/Git#Creating_a_fork