Better explaination of a \n meaning in regular expression.

Partially due to the issue #1790.
I guess the original author's intent was to specify that \r\n can be
either mangled thru a regex or an IO operation.

doc/Language/regexes.pod6

@@ -144,9 +144,12 @@ can be matched with C<\v>, and C<\s> matches any kind of whitespace.
 
 =item X<C<\n> and C<\N>|regex,\n;regex,\N>
 
-C<\n> matches a single, logical newline character. C<\n> is supposed to also
-match a Windows CR LF codepoint pair; though it's unclear whether the magic
-happens at the time that external data is read, or at regex match time.
+C<\n> matches a single, logical newline character.
+What is considered as a I<single newline character> is defined via the compile time
+variable L<$?NL>, and the L<newline pragma|/language/pragmas>.
+Therefore C<\n> is supposed to be able to either match a Unix-like newline "\n"
+or a Microsoft Windows style one "\r\n".
+
 C<\N> matches a single character that's not a logical newline.
 
 =item X<C<\s> and C<\S>|regex,\s;regex,\S>