There will be people reading this who have never used a Terminal, or typed at a command line, or called directories anything other than "folders".

There will be people reading this who have never installed anything that wasn't from an App Store.

There will be people reading this who have never heard of source control, branches, repos, or any of the other jargon in your document.

I think the number two thing project maintainers need to do is to stop making assumptions about the background and experience level of their potential contributors; or, if they do, to admit and outline them.

I write more about this here: http://opendesign.foundation/articles/import-designers/