fix typo

ChrisRackauckas · ChrisRackauckas · commit 3643bdcaa141 · 2023-10-18T23:50:27.000-04:00
diff --git a/docs/src/tutorials/modelingtoolkit.md b/docs/src/tutorials/modelingtoolkit.md
@@ -82,7 +82,7 @@ equations(sys)
 
 How did it do this? Let's look at the `observed` to see the relationships that it found:
 
-```@example
+```@example mtk
 observed(sys)
 ```
 
