added Table of contents to click  back and help navigate
Merge branch 'master' of https://github.com/specialorange/Usability-Engineering-CS5714-S14-project

# By tcjones
# Via tcjones
* 'master' of https://github.com/specialorange/Usability-Engineering-CS5714-S14-project:
  Add three Artifact pictures.
fixed section 18