Stop displaying features from / display
Add feature by feature title route

Refactored the code slightly to share the directory variable in $app.
Removed the default / route, this can be replaced with an overview page
of some kind.
Remove "I should see this feature step"

This functionality is tested in the DisplayFeature.feature
Add feature not found exception stub
Remove no longer required step
Add feature finder service
Change URL route to match index
Remove feature extractor

Moved functionality into once class, there was already non dry code
between the two classes, and if I want to change where the features are
stored later ( database ) I only want to change this class.