Add some documentation, clean up before merge.

Add:
        static/js/about.js, static/sass/(index, about).sass
                -Minor cleanup before merge into `develop`: remove a superfluous
                style rule, update header comments.

static/js/about.js

@@ -1,6 +1,10 @@
+/*
+ * @file Implements a parallax effect on the about page.
+ */
+
 var lastVertPos = $(window).scrollTop();
 
-function parallax(){
+$(window).scroll(function(e){
     var currVertPos = $(window).scrollTop();
     var delta = currVertPos - lastVertPos;
     $(".bg").each(function(){
@@ -8,8 +12,4 @@ function parallax(){
             delta * $(this).attr("speed") + "px");
     });
     lastVertPos = currVertPos;
-}
-
-$(window).scroll(function(e){
-    parallax();
 });

static/sass/about.sass

@@ -1,7 +1,11 @@
+/*
+ Stylesheet for `templates/about.html`
+ */
+
 @import mixins
 @import variables
 
-.bg
+div.bg
     $img-height: 650px
 
     position: fixed
@@ -17,7 +21,6 @@
 
     &#img-2
         background: url(../img/about/bg2.png) no-repeat
-        width: 100%
         height: $img-height + 530
         top: 550px
 

static/sass/index.sass

@@ -1,5 +1,5 @@
 /*
- Stylesheet for `index.html`.
+ Stylesheet for `templates/index.html`.
  */
 
 @import mixins