Update eventContext.md

Author: DeveloperTryingToCodeLikeOtherOfThem

docs/reference/game/eventContext.md

@@ -11,6 +11,7 @@ the EventContext object for the active scene.
 Manage the frame handlers for the scene and log the double the millisecond every 20 FPS.
 ``` ts
    const millis = control.millis();
+   // runs every frame at priority 20
    game.eventContext().registerFrameHandler(20, () => {
        const doubledMillis = millis * 2;
        console.log(doubledMillis);