Provide a few examples

And complete definition to make it clearer.

Author: JJ

doc/Type/Positional.pod6

@@ -4,22 +4,32 @@
 
 =SUBTITLE Object that supports looking up values by index
 
-    role Positional { ... }
+    role Positional[::T = Mu] { ... }
 
-Role for objects which support indexing them using the L«C< [ ] > postcircumfix operator|/language/operators#postcircumfix_[_]»
-(usually list-like objects).  Example types with Positional role
-include L<List|/type/List>, L<Array|/type/Array>, L<Range|/type/Range>, and L<Buf|/type/Buf>.
+Role for objects which support indexing them using the
+L«C< [ ] > postcircumfix operator|/language/operators#postcircumfix_[_]»
+(usually list-like objects). Example types with Positional role
+include L<List|/type/List>, L<Array|/type/Array>, L<Range|/type/Range>,
+and L<Buf|/type/Buf>.
 
 =head1 Methods
 
 =head2 method of
 
     method of()
 
-Returns the type constraint for elements of the positional container. Defaults
-to L<Mu|/type/Mu>.
+Returns the type constraint for elements of the positional container, that
+is, the C<T> in the definition above, which, as it can be seen, defaults
+to L<Mu|/type/Mu>. It is returned as a type object.
 
-=head1 Methods that should be provided
+=for code
+my @þ;
+say @þ.of.^name;   # OUTPUT: «Mu␤
+my Str @þð;
+say @þð.of.raku;   # OUTPUT: «Str␤»
+say (my int @).of; # OUTPUT: «(int)␤»
+
+=head1 Methods that should be provided by classes that mix in this role
 
 =head2 method elems