dir utils/core
types [a dictionary for add commands which would set the config file]
decks
bindings
dir cards
dir parent_notes

A card file will have the following:
schedule
tags
config
- reviewer
- editor
- parent_note

it may have some auxfiles. e.g.
basic
-(frontimage)
-(backimage)
-(frontaudio)
-(backaudio)
-front
-back
latex
-front.latex
-back.latex

Example:
a latex card would use the default reviewer (and supply all the required auxfiles for that); have no parent note; but use an editor to edit the two latex auxfiles and convert them to images on close. It would override f and b to edit the front and back latex respectively.

Example: 
image occlusion also use the default reviewer, but have no aux files. It would link to a parent note and use a custom editor that would open the parent_note (which can be configured however) for editing, probably in a separate window.

Example:
A type the answer question would not need a parent note, but it would use a custom editor to edit the type field(s) and it would use a custom reviewer to ask for user input.
