Update authentication.md

Author: shahincsejnu

content/en/docs/reference/access-authn-authz/authentication.md

@@ -207,7 +207,7 @@ spec:
 Service account bearer tokens are perfectly valid to use outside the cluster and
 
 can be used to create identities for long standing jobs that wish to talk to the
-Kubernetes API. To manually create a service account, simply use the `kubectl
+Kubernetes API. To manually create a service account, simply use the `kubectl`
 
 create serviceaccount (NAME)` command. This creates a service account in the
 current namespace and an associated secret.