Clarified glossary documentation (I think)

Fixed some typos, shortened some long or complex sentences, moved information between sections and removed some that I think don't belong in a glossary, or at least not under the current section. Added a proper ending to a clipped sentence.

Also changed "edge documents" to "edges" because if edges are documents isn't "edge documents" redundant?

I'm not as technically qualified as you, which is why I thought it would be appropriate for me to edit this document aimed at people like me. I question if all this information should be in a glossary. Should't a glossary briefly explain terms, rather than how they work, or how to work with them? By making it technical and sometimes not even answering the "what is" question (like the "Edge" subsection) you're only going to confuse the reader.

Please let me know if this is welcome, and if I should make smaller commits or something.