Escaping slash in $/ magic variable link

This removes the non-escaped / warning from `podchecker`

S99-glossary.pod

@@ -1089,7 +1089,7 @@ Code specific to the L</instruction set> of a hardware architecture. Compare wit
 L<Variable|/variable> that has a behavior of its own and that is denoted by
 a sigiless name with a non alphanumeric character.
 Unlike Perl 5 that has a profusion of magic variables, Perl 6 includes only the 
-magic variables L</$_>, L</$/> and L<$!>. They are L</block> L</scope>d and are implicitly
+magic variables L</$_>, L</"$/"> and L<$!>. They are L</block> L</scope>d and are implicitly
 defined at the beginning of each block.
 
 =head2 Match