Added a bit of pod markup to WDKeys.pm

lib/Selenium/Remote/WDKeys.pm

@@ -1,4 +1,17 @@
 package Selenium::Remote::WDKeys;
+
+=head1 NAME
+
+Selenium::Remote::WDKeys - Representation of keystrokes used by Selenium::Remote::WebDriver
+
+=cut
+
+=head1 DESCRIPTION
+
+The constant KEYS is defined here.
+
+=cut
+
 
 use strict;
 use warnings;