home: xdg: move 'less' variables to their module

modules/home/pager/default.nix

@@ -15,6 +15,7 @@ in
       # Clear the screen on start and exit
       LESS = "-R -+X -c";
       # Better XDG compliance
+      LESSKEY = "${config.xdg.configHome}/less/lesskey";
       LESSHISTFILE = "${config.xdg.dataHome}/less/history";
     };
   };