clarify with comments

src/domain/session/room/UnknownRoomViewModel.js

@@ -36,7 +36,11 @@ export class UnknownRoomViewModel extends ViewModel {
         try {
             const roomId = await this._session.joinRoom(this.roomIdOrAlias);
             // navigate to roomId if we were at the alias
+            // so we're subscribed to the right room status
+            // and we'll switch to the room view model once
+            // the join is synced
             this.navigation.push("room", roomId);
+            // keep busy on true while waiting for the join to sync
         } catch (err) {
             this._error = err;
             this._busy = false;