perlre: Simplify some text

By adding a word to a =heading, a sentence can be removed, and is
clearer.

But since some pod somewhere  may link to that heading, a section at the
end is added with the old name, and pointing to the new one.

Dan Book searched and found no instances in CPAN of the old heading
being linked to, but this guarantees that nothing breaks.

Author: khwilliamson

pod/perlre.pod

@@ -1348,9 +1348,7 @@ their punctuation character equivalents, however at the trade-off that you
 have to tell perl when you want to use them.
 X</p> X<p modifier>
 
-=head2 Quoting metacharacters
-
-(Also known as "escaping".)
+=head2 Quoting (escaping) metacharacters
 
 To cause a metacharacter to match its literal self, you precede it with
 a backslash.  Unlike some other regular expression languages, any
@@ -3413,6 +3411,10 @@ Subroutine call to a named capture group. Equivalent to C<< (?&I<NAME>) >>.
 
 =back
 
+=head2 Quoting metacharacters
+
+This section has been replaced by L</Quoting (escaping) metacharacters>.
+
 =head1 BUGS
 
 There are a number of issues with regard to case-insensitive matching