Fixed section numbering.

I had some sections at level 2 when they should have been
level 3.

code/custom.css

@@ -208,7 +208,7 @@
 <script>
     MathJax.Hub.Config({
                         TeX: {
-                           extensions: ["AMSmath.js"]
+                           extensions: ["AMSmath.js", "autobold.js"]
                            },
                 tex2jax: {
                     inlineMath: [ ['$','$'], ["\\(","\\)"] ],