Added proposed edits to Chapter 1.
slightly modify some of the proposed edits to reflect the existence of section 0
Merge pull request #1 from eplawless/Edit-Chapter1

Merge pull request, will commit some minor changes on top of this.
Merge pull request #2 from semmypurewal/eplawless

slightly modify some of the proposed edits to reflect the existence of s...
minor fixes to section 2
add note about functions behaving like values