clarified certain topics, added examples for reference, and fixed gra…

[bananaman47]

…mmatical mistakes in basic-chef-fluency

[anniehedgpeth]

Thanks for the PR, Naman! The only issue I see is line 379. I might change the second half to:
"The Berksfile retrieves cookbooks for use in your recipes from a Supermarket (Chef or internal). If you list metadata in your Berksfile, then you're telling it to grab everything that it can in your metadata.rb file from the Supermarket (Chef or internal). You may then add any other dependencies of those dependencies and where to find them if they're not in the Supermarket (i.e. local path or git link and branch). The metadata file handles versioned dependencies for chef-client when it's converging nodes, but a Berksfile just pulls cookbooks."

[bananaman47]

Hey Annie -- thanks for the quick reply. You're free to change it however you like! I just wanted to help clarify a few topics in a way that made sense to me and others.