Fix typo in multi-agent-debate.ipynb (#6288)

Author: larrytin

Diff for: python/packages/autogen-core/docs/src/user-guide/core-user-guide/design-patterns/multi-agent-debate.ipynb

@@ -291,7 +291,7 @@
                 "A --- B\n",
                 "|     |\n",
                 "|     |\n",
-                "C --- D\n",
+                "D --- C\n",
                 "```\n",
                 "\n",
                 "Each solver agent is connected to two other solver agents. \n",