Merge pull request #1 from gvwilson/gh-pages

Tidying up a few things in the bootcamp home page
Initial text on circulation card processing for librarian lessons

based on lesson idea from jhamrick https://github.com/jhamrick/library-exercise
Add more to Circulation Card example
Fix spelling and header size
Expand Circulation Card lesson
Touch up lesson
Finish off circulation card lesson
Formatting fixes