add a proper babycode help page

app.lua

@@ -65,4 +65,10 @@ app:get("/", function(self)
   return {redirect_to = self:url_for("all_topics")}
 end)
 
+app:get("babycode_guide", "/babycode", function(self)
+  self.me = util.get_logged_in_user_or_transient(self)
+  self.page_title = "babycode guide"
+  return {render = "babycode"}
+end)
+
 return app