chore: fix OpenCollective silver tier

Author: yyx990803

BACKERS.md

@@ -21,7 +21,7 @@ Funds donated via Patreon go directly to support Evan You's full-time work on Vu
     <img width="260px" src="https://raw.githubusercontent.com/vuejs/vuejs.org/master/themes/vue/source/images/codexyz.png">
   </a>
 </p>
-  
+
 <!--special end-->
 
 <h2 align="center">Platinum via Patreon</h2>
@@ -226,6 +226,12 @@ Funds donated via Patreon go directly to support Evan You's full-time work on Vu
 </table>
 <!--silver end-->
 
+<h4 align="center">Silver via OpenCollective</h4>
+
+<a href="https://opencollective.com/vuejs/tiers/silver-sponsors/0/website" target="_blank" rel="noopener noreferrer"><img src="https://opencollective.com/vuejs/tiers/silver-sponsors/0/avatar.svg"></a>
+<a href="https://opencollective.com/vuejs/tiers/silver-sponsors/1/website" target="_blank" rel="noopener noreferrer"><img src="https://opencollective.com/vuejs/tiers/silver-sponsors/1/avatar.svg"></a>
+<a href="https://opencollective.com/vuejs/tiers/silver-sponsors/2/website" target="_blank" rel="noopener noreferrer"><img src="https://opencollective.com/vuejs/tiers/silver-sponsors/2/avatar.svg"></a>
+
 <h2 align="center">Bronze via Patreon</h2>
 
 <!--bronze start-->

README.md

@@ -31,7 +31,7 @@ Funds donated via Patreon go directly to support Evan You's full-time work on Vu
     <img width="260px" src="https://raw.githubusercontent.com/vuejs/vuejs.org/master/themes/vue/source/images/codexyz.png">
   </a>
 </p>
-  
+
 <!--special end-->
 
 <h3 align="center">Platinum Sponsors</h3>