Add caveats doc.
Split off database functions.
Update ERD with PostgreSQL data types, add many-to-many for card decks.
Fixed a caveat.
Reorganized code into MVC sections.
Reorganized code into MVC sections.
Reorganized code into MVC sections.
Refactor classes to avoid future confusion.
Begin work on board model.
Begin work on the board view.
Comments about structure.
Card decks: support drawing a card (but not doing anything with it yet).