docs: add rapidproxy as gold sponsor (#5529)

README.md

@@ -12,6 +12,18 @@ frp is an open source project with its ongoing development made possible entirel
 
 <h3 align="center">Gold Sponsors</h3>
 <!--gold sponsors start-->
+<p align="center">
+  <a href="https://www.rapidproxy.io/?ref=frp" target="_blank">
+    <img width="420px" src="https://raw.githubusercontent.com/fatedier/frp/dev/doc/pic/sponsor_rapidproxy.png">
+    <br>
+    <b>High-performance residential and ISP proxies for developers</b>
+  </a>
+  <br>
+  <sub>90M+ residential IPs worldwide. Rotating IPs, sticky sessions, and traffic that never expires.</sub>
+  <br>
+  <sub>From $0.55/GB. Use RAPID10 for 10% off. Try it for free.</sub>
+</p>
+
 <p align="center">
   <a href="https://jb.gg/frp" target="_blank">
     <img width="420px" src="https://raw.githubusercontent.com/fatedier/frp/dev/doc/pic/sponsor_jetbrains.jpg">

README_zh.md

@@ -14,6 +14,18 @@ frp 是一个完全开源的项目，我们的开发工作完全依靠赞助者
 
 <h3 align="center">Gold Sponsors</h3>
 <!--gold sponsors start-->
+<p align="center">
+  <a href="https://www.rapidproxy.io/?ref=frp" target="_blank">
+    <img width="420px" src="https://raw.githubusercontent.com/fatedier/frp/dev/doc/pic/sponsor_rapidproxy.png">
+    <br>
+    <b>High-performance residential and ISP proxies for developers</b>
+  </a>
+  <br>
+  <sub>90M+ residential IPs worldwide. Rotating IPs, sticky sessions, and traffic that never expires.</sub>
+  <br>
+  <sub>From $0.55/GB. Use RAPID10 for 10% off. Try it for free.</sub>
+</p>
+
 <p align="center">
   <a href="https://jb.gg/frp" target="_blank">
     <img width="420px" src="https://raw.githubusercontent.com/fatedier/frp/dev/doc/pic/sponsor_jetbrains.jpg">