start on user guide html generator

rb/assets/user_guide.html.erb

@@ -0,0 +1,13 @@
+<html>
+  <head>
+    <title>RScons User Guide - Version <%= version %></title>
+    <style>
+      body {
+        max-width: 140ex;
+      }
+    </style>
+  </head>
+  <body>
+    <%= body %>
+  </body>
+</html>