Document the esc_2254 command line name option

RT#1466
Reviewed-by: NRich Salz <rsalz@openssl.org>

doc/apps/x509.pod

@@ -473,10 +473,15 @@ B<space_eq>, B<lname> and B<align>.
 
 =item B<esc_2253>
 
-escape the "special" characters required by RFC2253 in a field That is
+escape the "special" characters required by RFC2253 in a field. That is
 B<,+"E<lt>E<gt>;>. Additionally B<#> is escaped at the beginning of a string
 and a space character at the beginning or end of a string.
 
+=item B<esc_2254>
+
+escape the "special" characters required by RFC2254 in a field. That is
+the B<NUL> character as well as and B<()*>.
+
 =item B<esc_ctrl>
 
 escape control characters. That is those with ASCII values less than