Update formatting of some code samples, some wording, and changed phprc directory

I cleaned up some of the readme to be more clear and consistent, and then also updated the directory for phprc (as it was it didn't work, but googling found this: https://discussion.dreamhost.com/thread-136031.html )
Update README.md
Added conditional about the 5.4 subdir

I saw another pull request where @braunson suggested some servers need 5.4 subdir and some don't, so I updated the updated readme to reflect that.
Fixed typos
Merge branch 'master' of github.com:mattstauffer/dreamhost-composer-install into mattstauffer-master

Conflicts:
	README.md