add index item

Author: tbrowder

doc/Language/packages.pod6

@@ -113,9 +113,9 @@ the setting's outermost scope, use C<UNIT::OUTER> instead.
 
 =head1 Looking up names
 
-=head2 Interpolating into names
+=head2 X<Interpolating into names>
 
-X<|::()> You may L<interpolate|interpolating|/language/packages#Interpolating> a string into a package or variable name
+X<|::()> You may L<interpolate|/language/packages#Interpolating> a string into a package or variable name
 using C<::($expr)> where you'd ordinarily put a package or variable
 name. The string is allowed to contain additional instances of C<::>,
 which will be interpreted as package nesting. You may only interpolate