missing link Update regexes.rakudoc

a link to the same file only needs `#href`

doc/Language/regexes.rakudoc

@@ -2961,7 +2961,7 @@ The C<:?> metacharacter works exactly like C<:!>, except that it enables frugal
 backtracking.  It is thus closely related to C<?> L<frugal quantifier
 modifier|/language/regexes#Greedy_versus_frugal_quantifiers:_?>; again,
 however C<:?> can be used after non-quantifier atoms.  This includes contexts in
-which C<?> would be the L<zero or one|/language/regex#Zero_or_one:_?> quantifier
+which C<?> would be the L<zero or one|#Zero_or_one:_?> quantifier
 (instead of providing backtracking control):
 
 =begin code