Add ability to define custom link for ToC, and add link for spiderable

docs/client/full-api/tableOfContents.html

@@ -12,7 +12,7 @@
     {{/if}}
     {{#if type "section"}}
       {{#nav_section}}
-        <a href="#/full/{{id}}" class="{{maybe_current}} {{style}}">
+        <a href="{{link}}" class="{{maybe_current}} {{style}}">
           {{#if prefix}}{{prefix}}.{{/if}}{{#if instance}}<i>{{instance}}</i>.{{/if}}{{name}}
         </a>
       {{/nav_section}}

docs/client/full-api/tableOfContents.js

@@ -317,6 +317,7 @@ var toc = [
     "random",
     "stylus",
     "showdown",
+    {name: "spiderable", link: "https://atmospherejs.com/meteor/spiderable"},
     "stylus",
     "underscore",
     "webapp"
@@ -364,9 +365,12 @@ Template.nav.helpers({
         else {
           if (typeof(item) === "string")
             item = {name: item};
+
+          var id = item.name && name_to_id(item.name) || undefined;
+
           ret.push(_.extend({
             type: "section",
-            id: item.name && name_to_id(item.name) || undefined,
+            link: "#/full/" + id,
             depth: depth,
             style: ''
           }, item));