[io grant] Finish up IO::Path.dirname

- Add links to volume/basename
- Include an example with IO::Path that has a volume

Author: zoffixznet

doc/Type/IO/Path.pod6

@@ -259,12 +259,12 @@ Defined as:
     method dirname(IO::Path:D:)
 
 Returns the directory name portion of the path object. That is, it returns
-the path excluding the volume and the base name.
-
-    say IO::Path.new("/home/camelia/myfile.p6").dirname;    # OUTPUT: «/home/camelia␤»
-    say IO::Path.new("/home/camelia").dirname;              # OUTPUT: «/home␤»
-    say IO::Path.new("/home").dirname;                      # OUTPUT: «/␤»
+the path excluding the L<volume|/routine/volume> and the
+L<base name|/routine/basename>.
 
+    say IO::Path.new("/home/camelia/myfile.p6").dirname; # OUTPUT: «/home/camelia␤»
+    say IO::Path::Win32.new("C:/home/camelia").dirname;  # OUTPUT: «/home␤»
+    say IO::Path.new("/home").dirname;                   # OUTPUT: «/␤»
 
 =head2 method volume