Added two user definable custom configuration cookbooks and template
attributes for sumo.json and sumo.conf.  These attributes allow someone
using the community sumologic-collector cookbook to inject their own
custom sumo.json and sumo.conf templates through custom cookbooks
directly or from a wrapper cookbook.  Included defaults mean that all
current behavior remains the same unless a user wants to introduce
custom configuration cookbooks and templates.
Updated comments for sumo.json and sumo.conf custom cookbook
documentation.
Fixed some typos in README.
Merge pull request #6 from rayrod2030/master

Introduce user defined configuration cookbooks for customizing sumo.json and/or sumo.conf