fixed typo in doc (secrets)

docs/secrets.md

@@ -302,7 +302,7 @@ A secret is only sent to a node if a pod on that node requires it.  It is not
 written to disk.  It is stored in a tmpfs.  It is deleted once the pod that
 depends on it is deleted.
 
-On most Kubernetes-project-maintained distributions, commuication between user
+On most Kubernetes-project-maintained distributions, communication between user
 to the apiserver, and from apiserver to the kubelets, is protected by SSL/TLS.
 Secrets are protected when transmitted over these channels.