enable $ inline expressions so the example markdown doc works, $ can be escaped using \$ so shouldn't be much of an issue

lib/gollum/templates/layout.mustache

@@ -38,7 +38,7 @@
   <script type="text/javascript">
   window.MathJax = {
     tex2jax: {
-      inlineMath:  [ ['\\(','\\)'] ],
+      inlineMath:  [ ['$','$'], ['\\(','\\)'] ],
       displayMath: [ ['$$','$$'], ['\\[','\\]'] ],
       processEscapes: true
     },

lib/gollum/templates/livepreview.mustache

@@ -45,7 +45,7 @@ var require = {
 <script type="text/javascript">
 window.MathJax = {
 tex2jax: {
-  inlineMath:  [ ['\\(','\\)'] ],
+  inlineMath:  [ ['$','$'], ['\\(','\\)'] ],
   displayMath: [ ['$$','$$'], ['\\[','\\]'] ],
   processEscapes: true
 },