fix syntax highlighting

ChrisRackauckas · ChrisRackauckas · commit f817ca75ad34 · 2021-03-11T19:46:29.000-05:00
diff --git a/src/systems/pde/pdesystem.jl b/src/systems/pde/pdesystem.jl
@@ -8,7 +8,7 @@ $(FIELDS)
 
 # Example
 
-```
+```julia
 using ModelingToolkit
 
 @parameters t, x
