Add package sync workflow

PackageSource/com.foldcc.cc-framework.BriskGameServer/README.md

@@ -8,6 +8,10 @@ The active Unity project source currently lives under:
 - `Assets/BriskSdk/Samples/QuickStart`
 - `Assets/Scenes/BriskQuickStartScene.unity`
 
+Sync package content from the Unity source project with:
+
+- `Tools/Sync-BriskPackage.ps1`
+
 ## Included runtime modules
 
 - Bootstrap and initialization