Address comments.

packages/cells/src/widget.ts

@@ -679,7 +679,7 @@ class MarkdownCell extends Cell {
       signal: this.model.contentChanged,
       timeout: RENDER_TIMEOUT
     });
-    this._monitor.activityStopped.connect(()=>{
+    this._monitor.activityStopped.connect(() => {
       if (this._rendered) {
         this.update();
       }

packages/fileeditor/src/widget.ts

@@ -140,6 +140,10 @@ class FileEditor extends CodeEditorWrapper {
     this.title.label = path.split('/').pop();
   }
 
+  /**
+   * Handle a change to the collaborators on the model
+   * by updating UI elements associated with them.
+   */
   private _onCollaboratorsChanged(): void {
     // If there are selections corresponding to non-collaborators,
     // they are stale and should be removed.