Add explanation to setShouldPopAllStateOnUP(true) in NavigationRoot

Author: WojtekBoman

src/libs/Navigation/NavigationRoot.tsx

@@ -167,6 +167,9 @@ function NavigationRoot({authenticated, lastVisitedPath, initialUrl, onReady}: N
             return;
         }
 
+        // After resizing the screen from wide to narrow, if we have visited multiple central screens, we want to go back to the LHN screen, so we set shouldPopAllStateOnUP to true.
+        // Now when this value is true, Navigation.goBack with the option {shouldPopToTop: true} will remove all visited central screens in the given tab from the navigation stack and go back to the LHN.
+        // More context here: https://github.com/Expensify/App/pull/59300
         if (!shouldUseNarrowLayout) {
             return;
         }