Add a comment to the top of the javascript.

assets/bookmark.js

@@ -1,4 +1,7 @@
-
+/*
+Stores the scroll location on a story to local storage, and re-scroll to the
+position next time the page is loaded.
+*/
 window.onbeforeunload = function(e) {
 	localStorage.setItem(window.location.pathname,window.scrollY)
 }