fix typo

no dash needed

Author: coke

doc/Language/exceptions.pod6

@@ -13,9 +13,9 @@ All built-in exceptions inherit from L<Exception>, which provides some basic
 behavior, such as storing a backtrace and providing an interface for the
 backtrace printer.
 
-=head1 Ad-hoc exceptions
+=head1 Ad hoc exceptions
 
-Ad-hoc exceptions work just like in traditional Perl 5, one can simply use
+Ad hoc exceptions work just like in traditional Perl 5, one can simply use
 C<die> with a message as to what went wrong:
 
     die "oops, something went wrong";