docs: refine README usage and ecosystem note

Author: afc163

README.md

@@ -1,17 +1,10 @@
 <div align="center">
   <h1>@rc-component/mentions</h1>
+  <p><sub>Part of the Ant Design ecosystem.</sub></p>
   <img alt="Ant Design" height="32" src="https://gw.alipayobjects.com/zos/bmw-prod/ae669a89-0c24-40ff-a91d-2b83497170f6.svg" />
   <p>💬 React mentions textarea with searchable suggestions and keyboard navigation.</p>
 </div>
 
-<p align="center">
-  <sub>
-    <a href="https://ant.design">
-      <img alt="Ant Design" src="https://gw.alipayobjects.com/zos/rmsportal/KDpgvguMpGfqaHPjicRK.svg" height="16">
-    </a>
-    Part of the Ant Design ecosystem.
-  </sub>
-</p>
 
 <div align="center">