Update for_novice_contributors.md

[RJDan]

I have done some edits to a few sentences to make the sentences a bit easier to read. I've also re-arranged some of the glossary items to make it easier for novices to understand and learn the new terms.

[hoytpr]

Your edits look good.

Should we consider being specific about whether we are talking about nouns or verbs? For example:

• fork (v. GitHub-specific action)
  to copy a repository...

• fork (n. GitHub specific element)
  a copy of a repository created by forking

same with

• a push, to push
• a pull, to pull

(a novice is a novice)

[RJDan]

I think it would be good to have a separate definition for the nouns and verbs. It's not something I thought about but now that you mention it, I think it helps a bunch.