doc update

docs/quickstart.mdx

@@ -50,7 +50,8 @@ class _MyAppState extends State<MyApp> {
     _thermionFlutterPlugin = ThermionFlutterPlugin();    
     _thermionViewer = _thermionFlutterPlugin.createViewer();  
   }
-}```
+}
+```
 
 
 4. Add a `ThermionWidget` to your widget hierarchy 
@@ -73,7 +74,8 @@ class _MyAppState extends State<MyApp> {
                 ) 
             )
         ]);  
-}}```
+}}
+```
 
 4. Add a button to load the model when pressed
 
@@ -98,7 +100,8 @@ class _MyAppState extends State<MyApp> {
                 // TODO
             }))
         ]);  
-}}```
+}}
+```
 
 5. Load a skybox and the glb asset
 ```dart