Update InfraCluster contract to include Paused condition

Author: theobarberbany

docs/book/src/developer/providers/contracts/infra-cluster.md

@@ -308,6 +308,8 @@ If a condition with type `Ready` exist, such condition will be mirrored in Clust
 Please note that the `Ready` condition is expected to surface the status of the InfraCluster during its own entire lifecycle,
 including initial provisioning, the final deletion process, and the period in between these two moments.
 
+Provider implementers SHOULD implement `Status.Conditions[Paused]` to report if the cluster is paused. It should check if 'spec.paused' is set on the cluster, and for the paused annotation. Implementing this condition is currently optional, but we may revisit this in the future.
+
 See [Cluster API condition proposal] for more context.
 
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