use settingslogic gem for settings rather than home-grown solution
Implement filter to generate amazon urls
Make amazon filter a bit more readable
helper -> filters (lol copy-paste)
Add expectation :text to filter engine for filters that need to be executed before anything happens with Markdown
Implement filter for "lazy urls"
TextFilterEngine now uses an instance to keep track of stuff
Implement heading shifting filter. It forces the heading levels of a markdown document to be relative to a certain starting level.