Chapter 9 Basic Concepts

I really like the inclusion of this section. But I definitely think this area of the documentation should be highlighted a lot more from the start. Under Software Tools -> Get Started, I think there should be some type of reference/links to the Basic Concepts. Nice graphics too, I like the one on the Blockchain Nodes section. I think fleshing out the Basic Concepts section as a whole would be valuable for people just getting started.