chore: update quickstart

examples/flutter/quickstart/lib/main.dart

@@ -79,6 +79,13 @@ class _MyHomePageState extends State<MyHomePage> {
     await _thermionViewer!.loadSkybox("assets/default_env_skybox.ktx");
     await _thermionViewer!.loadIbl("assets/default_env_ibl.ktx");
 
+    // The underlying Filament rendering engine exposes a number of 
+    // post-processing options (anti-aliasing, bloom, etc).
+    // Post-processing is disabled by default, but most users will want to 
+    // enable it for color correction.
+    // If you're not sure what you're doing, always set this to true.
+    await _thermionViewer!.setPostProcessing(true);
+
     // Finally, you need to explicitly enable rendering. Setting rendering to
     // false is designed to allow you to pause rendering to conserve battery life
     await _thermionViewer!.setRendering(true);
@@ -87,7 +94,7 @@ class _MyHomePageState extends State<MyHomePage> {
   }
 
   Future _unload() async {
-    // when you are no longer need the 3D viewport:
+    // when you've finished rendering and you no longer need a 3D viewport:
     // 1) remove all instances of ThermionWidget from the widget tree
     // 2) remove all local references to the ThermionViewer
     // 3) call dispose on the ThermionViewer