sticky footer docs and example.

doc-src/content/examples/compass/layout/sticky-footer.haml

@@ -0,0 +1,8 @@
+---
+title: Compass Sticky Footer Example
+description: How to use the sticky footer mixin.
+framework: compass
+stylesheet: compass/layout/_sticky_footer.sass
+example: true
+---
+= render "partials/example"

doc-src/content/examples/compass/layout/sticky-footer/markup.haml

@@ -0,0 +1,16 @@
+.example
+  #layout
+    #header
+      %h1 Sticky Footer Example
+
+    %p
+      This is the main content area.
+    %p
+      In this example you should pretend that the red box
+      is actually the browser window.
+    %p
+      Because, being a contrived example, it's not actually sticking
+      to the bottom of the page.
+    #layout_footer
+  #footer
+    This is the footer area.

doc-src/content/examples/compass/layout/sticky-footer/stylesheet.sass

@@ -0,0 +1,18 @@
+@import compass/reset.sass
+@import compass/layout.sass
+
++sticky-footer(72px, "#layout", "#layout_footer", "#footer")
+
+#header
+  :background #999
+  :height 72px
+
+#footer
+  :background #ccc
+
+.example
+  height: 500px
+  border: 3px solid red
+  
+  p
+    margin: 1em 0.5em

doc-src/content/reference/compass/layout/sticky_footer.haml

@@ -8,4 +8,5 @@ classnames:
 ---
 - render 'reference' do
   %p
-    Lorem ipsum dolor sit amet.
+    This module provides tools needed to lay out your footer such
+    that it sticks to the bottom of the page.

frameworks/compass/stylesheets/compass/layout/_sticky_footer.sass

@@ -1,7 +1,11 @@
-// Based on http://ryanfait.com/resources/footer-stick-to-bottom-of-page/
+//
-// Mix into the top level.
+  Based on a [blog post by Ryan Fait](http://ryanfait.com/resources/footer-stick-to-bottom-of-page/).
-// Footer element must be outside of root wrapper element.
+
-// Footer must be a fixed height.
+  Must be mixed into the top level of your stylesheet.
+
+  Footer element must be outside of root wrapper element.
+
+  Footer must be a fixed height.
 
 =sticky-footer(!footer_height, !root_selector = "#root", !root_footer_selector = "#root_footer", !footer_selector = "#footer")
   html, body