added marionette logo url

public/icons/docs/marionette/SOURCE

@@ -1 +1,2 @@
-https://github.com/marionettejs/marionettejs.com
+https://github.com/marionettejs/marionettejs.com/blob/master/src/logo/logo.svg
+https://github.com/marionettejs/marionettejs.com