docs: update sync-wave documentation

Signed-off-by: chansuke <[email protected]>

docs/user-guide/sync-waves.md

@@ -4,9 +4,9 @@
 
 <iframe width="560" height="315" src="https://www.youtube.com/embed/zIHe3EVp528" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
-Argo CD executes a sync operation in a number of steps. At a high-level, there are three phases *pre-sync*, *sync* and *post-sync*.  
+Argo CD executes a sync operation in a number of steps. At a high-level, there are three phases *pre-sync*, *sync* and *post-sync*.
 
-Within each phase you can have one or more waves, that allows you to ensure certain resources are healthy before subsequent resources are synced.   
+Within each phase you can have one or more waves, that allows you to ensure certain resources are healthy before subsequent resources are synced.
 
 ## How Do I Configure Phases?
 
@@ -32,17 +32,23 @@ metadata:
 
 Hooks and resources are assigned to wave zero by default. The wave can be negative, so you can create a wave that runs before all other resources.
 
+### Can Multiple Resources Share the Same Wave?
+
+Yes, multiple resources can share the same sync-wave value. Resources with the same sync-wave are processed together.
+
+Within a wave, resources are ordered by their kind (e.g. namespaces first) and then by their name.
+
 ## How Does It Work?
 
 When Argo CD starts a sync, it orders the resources in the following precedence:
 
 * The phase
 * The wave they are in (lower values first for creation & updation and higher values first for deletion)
 * By kind (e.g. [namespaces first and then other Kubernetes resources, followed by custom resources](https://github.com/argoproj/gitops-engine/blob/bc9ce5764fa306f58cf59199a94f6c968c775a2d/pkg/sync/sync_tasks.go#L27-L66))
-* By name 
+* By name
 
 It then determines the number of the next wave to apply. This is the first number where any resource is out-of-sync or unhealthy.
- 
+
 It applies resources in that wave. 
 
 It repeats this process until all phases and waves are in-sync and healthy.