Update pod.pod6

Latest Rakudo compiles and supplies Pod::Defn, so this is now rendered as dd/dt items.
Eliminate references to future and to specific renderers.

doc/Language/pod.pod6

@@ -320,16 +320,14 @@ When you're not blue.
 When you're not happy.
 =end code
 
-will be rendered with C<Pod::To::HTML> this way:
+will be rendered as
 
 =defn Happy
 When you're not blue.
 
 =defn Blue
 When you're not happy.
 
-Which, for the time being, is a simple HTML paragraph, but the format might change in the future.
-
 =head3 Multi-level lists
 
 Lists may be multi-level, with items at each level specified using the C<=item1>, C<=item2>, C<=item3>, etc. blocks.