Add short description for Backbone part

services/index.md

@@ -34,6 +34,8 @@ Cloud.
 </div>
 
 ## Backbone
+High-performance trusted network infrastructure with unified basic services.
+
 <div class="flex-cards">
 {%- assign posts = site.pages | where_exp: "item", "item.path contains 'services/backbone'" -%}
 {% for post in posts -%}