Add short description of classifications to products guide
add TODO for return authorizations
Add Activators guide
Freeze to kramdown 1.0.1, nanoc 3.6.1

Future versions should be tested first (run "bundle exec nanoc compile",
ensure things don't blow up) before version bumping
Use bash, not shell to indicate shell highlighting

Stupid, I know.
Fix syntax error in Activators guide
Add Activators to dev sidebar
WIP promotions guide
Add details about path matching, accessing promotion data and what Rule#eligible? should return to promotions guide
Fixed code styles
Fixed link - also using markdown instead of link to
Move chapter index stuff into relevant folders
New About the Code guide
Porting of original source code guide (WIP)
Minor syntax problem
Streamlined guide titles
Fixed table on navigating guide
Use fenced code blocks in promotions and activators guides
Add promotions to sidebar
Add link to activators