Address review comments.

docs/admin/federation/kubefed.md

@@ -92,7 +92,7 @@ aware of the clusters that it is responsible for managing. You can
 teach the federation control plane about a cluster by joining that
 cluster to the federation.
 
-Joining a cluster to a federation is as simple as running:
+To join a cluster to a federation run:
 
 ```
 kubfed join gondor --host-cluster-context=rivendell
@@ -119,21 +119,25 @@ for the clusters don't follow RFC 1035 label naming rules. In these
 cases, you could specify a cluster name that conforms to the RFC 1035
 label naming rules and specify the cluster context using the
 `--cluster-context` flag. For example, if context of the cluster your
-are joining is `gondor_has_no_king-gondor_needs_no_king`, then you can
+are joining is `gondor_needs-no_king`, then you can
 join the cluster by running:
 
 ```shell
-kubfed join gondor --host-cluster-context=rivendell --cluster-context=gondor_has_no_king-gondor_needs_no_king
+kubfed join gondor --host-cluster-context=rivendell --cluster-context=gondor_needs-no_king
 ```
 
 #### Secret name
 
-Cluster credentials required by the federation control plane as described above are stored as a secret in the host cluster. The name of the secret is also derived from the cluster name. 
+Cluster credentials required by the federation control plane as
+described above are stored as a secret in the host cluster. The name
+of the secret is also derived from the cluster name.
 
 However, the name of a secret object in Kubernetes should conform
-to the subdomain name specification described in RFC 1123. If this isn't case, you can pass the secret name to `kubefed join` using the
+to the subdomain name specification described in RFC 1123. If this
+isn't case, you can pass the secret name to `kubefed join` using the
 `--secret-name` flag. For example, if the cluster name is `noldor` and
-the secret name is `11kingdom`, you can join the cluster by running:
+the secret name is `11kingdom`, you can join the cluster by
+running:
 
 ```shell
 kubfed join noldor --host-cluster-context=rivendell --secret-name=11kingdom