Update InfraCluster contract to include Pausing rule

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

@@ -335,6 +335,12 @@ the implication of this choice which are described both in the document above an
 
 </aside>
 
+### InfraCluster: Pausing
+
+Providers SHOULD implement the pause behaviour for every object with a reconciliation loop. This is done by checking if `spec.paused` is set, or for the paused annotation: `cluster.x-k8s.io/paused`.
+
+If implementing the pause behavior, providers SHOULD surface the paused status of an object using the Paused condition: `Status.Conditions[Paused]`.
+
 ### InfraCluster: terminal failures
 
 Each InfraCluster SHOULD report when Cluster's enter in a state that cannot be recovered (terminal failure) by