Add ability to toggle presenter by clicking name

src/GridDemo.jsx

@@ -20,6 +20,19 @@ export function GridDemo() {
     ]);
   }, [stream]);
 
+  const togglePresenter = useCallback((selectedParticipant) => {
+    setParticipants((participants) =>
+      participants.map((participant) =>
+        participant === selectedParticipant
+          ? {
+              ...participant,
+              presenter: !participant.presenter,
+            }
+          : participant
+      )
+    );
+  }, []);
+
   const removeParticipant = useCallback((key) => {
     setParticipants((participants) =>
       participants.filter((participant) => participant.userId !== key)
@@ -43,7 +56,7 @@ export function GridDemo() {
           </button>
         )}
       </div>
-      <VideoGrid participants={participants} />
+      <VideoGrid participants={participants} onClickNameTag={togglePresenter} />
     </div>
   );
 }