Update Carbon placement code

docs/content/changelog.md

@@ -16,6 +16,7 @@ weight = 3
   - Add fallback search strategy for @crate search. Fix {{ issue(id=96) }}.
   - Only open update page once a day if the auto-update is on. Fix {{ issue(id=97) }}.
   - Add more useful tips for the `:help` command.
+  - Compress history's JSON data slightly.
 - Bugfix:
   - Add validation when auto index std search-index. Fix {{ issue(id=99) }}.
   - Fix compatibility issue of the new const-since link in Rust docs page.

docs/sass/index.scss

@@ -1,3 +1,5 @@
+@import "carbon";
+
 .content img {
   width: 75%;
   height: auto;

docs/templates/index.html

@@ -25,7 +25,6 @@
       content="{{ config.extra.meta_description }}">
 <meta name="twitter:image" content="https://rust.extension.sh/banner.png">
 <link rel="stylesheet" href="{{ get_url(path="index.css") }}">
-<link rel="stylesheet" href="{{ get_url(path="carbon.css") }}">
 {% endblock head %}
 
 {% block hero %}
@@ -92,9 +91,7 @@
 
 {% block sidebar %}
 <div class="sidebar">
-    <script async type="text/javascript"
-            src="//cdn.carbonads.com/carbon.js?serve=CEBIL27E&placement=rustextensionsh"
-            id="_carbonads_js"></script>
+    <script async type="text/javascript" src="//cdn.carbonads.com/carbon.js?serve=CEBIL27E&placement=extensionsh" id="_carbonads_js"></script>
 </div>
 {% endblock %}