altered CSS to more closely match github's markdown css.

Main chaings:
Padding between LIs = 0px
Fixed page-width: 920px
H1, H2, H3: Margin-top: 20px; margin-bottom: 10px

lib/gollum/frontend/public/gollum/css/gollum.css

@@ -21,7 +21,9 @@ body, html {
 #wiki-wrapper {
   margin: 0 auto;
   overflow: visible;
-  width: 80%;
+  width: 920px;
+  padding-left:20px;
+  padding-right:20px;
 }
 
 a:link {

lib/gollum/frontend/public/gollum/css/template.css

@@ -97,20 +97,16 @@ a.absent {
 .markdown-body h1 {
   font-size: 28px;
   color: #000;
-  margin-top: 50px;
-  margin-bottom: 20px;
+  margin-top: 20px;
+  margin-bottom: 10px;
 }
 .markdown-body h2 {
   font-size: 24px;
   border-bottom: 1px solid #ccc;
   color: #000;
-  margin-top: 40px;
-  margin-bottom: 20px;
 }
 .markdown-body h3 {
   font-size: 18px;
-  margin-top: 30px;
-  margin-bottom: 15px;
 }
 .markdown-body h4 {
   font-size: 16px;
@@ -127,10 +123,13 @@ a.absent {
 .markdown-body ul,
 .markdown-body ol,
 .markdown-body dl,
-.markdown-body li,
 .markdown-body table,
 .markdown-body pre {
-  margin: 15px 0;
+  margin: 0px 0;
+  margin-bottom: 15px;
+}
+.markdown-body li {
+  margin: 0px;
 }
 .markdown-body hr {
   background: transparent url(../images/dirty-shade.png) repeat-x 0 0;
@@ -146,12 +145,9 @@ a.absent {
 .markdown-body>h5:first-child,
 .markdown-body>h6:first-child {
 }
-.markdown-body h1+h2{
+.markdown-body h1+h2+h3{
   margin-top: 30px;
 }
-.markdown-body h2+h3{
-  margin-top: 10px;
-}
 .markdown-body a:first-child h1,
 .markdown-body a:first-child h2,
 .markdown-body a:first-child h3,