update docker/default to runtime/default

Author: wangzhen127

node/seccomp.md

@@ -197,7 +197,7 @@ profiles to be opaque to kubernetes for now.
 
 The following format is scoped as follows:
 
-1.  `docker/default` - the default profile for the container runtime, can be
+1.  `runtime/default` - the default profile for the container runtime, can be
     overwritten by the following two.
 2.  `unconfined` - unconfined profile, ie, no seccomp sandboxing
 3.  `localhost/<profile-name>` - the profile installed to the node's local seccomp profile root