NEW Add font-icon for site tree blog holder and posts

src/Model/Blog.php

@@ -130,7 +130,7 @@ class Blog extends Page implements PermissionProvider
      */
     private static $description = 'Adds a blog to your website.';
 
-    private static $icon = 'silverstripe/blog:client/images/site-tree-icon.png';
+    private static $icon_class = 'font-icon-p-posts';
 
     /**
      * {@inheritdoc}

src/Model/BlogPost.php

@@ -55,6 +55,11 @@ class BlogPost extends Page
      */
     private static $table_name = 'BlogPost';
 
+    /**
+     * @var string
+     */
+    private static $icon_class = 'font-icon-p-post';
+
     /**
      * @var array
      */