Adds «type object» refs #728

Author: JJ

doc/Language/glossary.pod6

@@ -1115,6 +1115,10 @@ a simple string.  (The formatting code objects are interC<twine>d with the
 strings.) The strings may be empty (as shown in the example).
 A twine with no formatting code will contain one simple string.
 
+=head1 Type objects
+
+A L<type object|https://docs.perl6.org/language/classtut#index-entry-type_object> is an object that is used to represent a type or a class. Since in object oriented programming everything is an object, classes are objects too, which inherit from the ur-class which, in our case, is L<Mu>.
+
 =head1 value
 X<|value>