message: Add more commentary around how the roomCache works
diff: @@ -54,7 +54,24 @@ class RoomListStore extends Store {
  "im.vector.fake.archived": [],
  },
  ready: false,
  - roomCache: {}, // roomId => { cacheType => value }
  +
  + // The room cache stores a mapping of roomId to cache record.
  + // Each cache record is a key/value pair for various bits of
  + // data used to sort the room list. Currently this stores the
  + // following bits of informations:
  + // "timestamp": number, The timestamp of the last relevant
  + // event in the room.
  + // "notifications": boolean, Whether or not the user has been
  + // highlighted on any unread events.
  + // "unread": boolean, Whether or not the user has any
  + // unread events.
  + //
  + // All of the cached values are lazily loaded on read in the
  + // recents comparator. When an event is received for a particular
  + // room, all the cached values are invalidated - forcing the
  + // next read to set new values. The entries do not expire on
  + // their own.
  + roomCache: {},
  };
  }
  