AppCards

• Up through version 0.0.6 I've been using Miro Cards that can be edited on the board. This makes it too easy to accidentally overwrite titles.
• When selecting a card from an older version, it will be migrated to a new AppCard and then removed.
  • I couldn't get it to reliably place the new card over the old one, so it just puts it in the center of the viewport.
• All new cards are AppCards