Add description to e2e failure domain test case

test/e2e/failure_domains_test.go

@@ -38,6 +38,10 @@ const (
 )
 
 // Note: Still has "only-for-validation" label.
+// Tests if:
+//   - the control plane nodes are spread across the defined failure domains
+//   - the VMs are deployed on the correct Prism Element cluster and subnet
+//   - the correct failure domain conditions are applied to the nutanixCluster object
 var _ = Describe("Nutanix failure domains", Label("capx-feature-test", "failure-domains", "only-for-validation", "slow", "network"), func() {
 	const specName = "failure-domains"