Document mkdir is like $ mkdir -p

[Coke]++

doc/Type/IO/Path.pod6

@@ -273,8 +273,11 @@ https://en.wikipedia.org/wiki/File_system_permissions#Numeric_notation>
 specified as an integer (thought still subject to L<umask|
 https://en.wikipedia.org/wiki/Umask>).
 
+Creates parent directories, as needed. That is, C<mkdir "foo/bar"> will 
+create C<foo> if it does not exist.
+
 Throws an exception of type L<X::IO::Mkdir> if the
-directory cannot be created, except for the C<*@dirnames> form which
+directory cannot be created, except for the C<*@dirnames> form, which
 returns the names of the directories that were successfully created.
 
 =head2 routine rmdir