minor fix

layers/+lang/perl5/README.org

@@ -15,7 +15,7 @@
 * Description
 This layer adds support for the Perl5 language.
 
-** Features
+** Features:
 - syntactic and semantic checking via flycheck with =perl -c= and =plsense=
 - jump to symbol via dump jump
 - interactive debug via [[https://github.com/realgud/realgud][realgud]] with [[http://search.cpan.org/~rocky/Devel-Trepan-0.73/lib/Devel/Trepan.pm][trepan.pl]]