Update README.md

Author: cloudwebrtc

example/README.md

@@ -4,5 +4,12 @@ A new Flutter project.
 
 ## Getting Started
 
+Make sure your flutter is using the `dev` channel.
+
+- `flutter channel dev`
 - `./scripts/project_tools.sh create`
 - `flutter run`
+
+## Fro Desktop or Web
+- `flutter run -d macos`
+- `flutter run -d web|chrome`