Minor rewording of the intro
Uses blockquote instead of p.

- More semantic markup
- Uses "human readable" html entities
Merge branch 'add-blockquote-to-lesson-3' of github.com:cloud8421/tutorials into cloud8421-add-blockquote-to-lesson-3
move Claudio's clarification into specific tutorials
Merge branch 'master' of github.com:codebar/tutorials