Add context to explain why we fetch roomstate in threads

src/models/event-timeline-set.ts

@@ -515,7 +515,7 @@ export class EventTimelineSet extends EventEmitter {
      * @param {MatrixEvent} event Event to be added
      * @param {string?} duplicateStrategy 'ignore' or 'replace'
      * @param {boolean} fromCache whether the sync response came from cache
-     * @param {boolean} fromCache whether the sync response came from cache
+     * @param roomState the state events to reconcile metadata from
      */
     public addLiveEvent(
         event: MatrixEvent,

src/models/thread.ts

@@ -73,6 +73,10 @@ export class Thread extends EventEmitter {
             this.root = event.getId();
         }
 
+        // all the relevant membership info to hydrate events with a sender
+        // is held in the main room timeline
+        // We want to fetch the room state from there and pass it down to this thread
+        // timeline set to let it reconcile an event with its relevant RoomMember
         const roomState = this.room.getLiveTimeline().getState(EventTimeline.FORWARDS);
 
         event.setThread(this);