Add another gym about scene switching

docs/gyms/cross-timeline-interactions/gym_main.dtl

@@ -50,7 +50,24 @@ Miko (neutral): Which pattern would you like to explore?
     Miko (joy): The variable itself is the jump target!
     jump gym_pattern8_dynamic_label/start
 
+- More patterns...
+    Miko (smile): There's more to explore on the next page!
+    jump menu_p2
+
 - I've seen enough. Goodbye!
     Miko (smile): Thanks for exploring! Come back anytime.
     Advisor (pl5): Until next time.
     [end_timeline]
+
+label menu_p2
+
+Miko (neutral): More patterns to explore:
+
+- 9. Scene switching (Dialogic ↔ gameplay)
+    Miko (smile): This one changes scenes — a timeline, then a minigame, then back!
+    Advisor (pl5): I'll take you to the intro, which will trigger the minigame.
+    Miko (neutral): Press the button 5 times to return.
+    jump gym09_intro/
+
+- Back to first page
+    jump menu