docs: fix dead PR badge link (use GitHub PRs URL)

Author: internet-dot

README.md

@@ -15,7 +15,7 @@
 </p>
 
 <p align="center">
-  <a href="http://makeapullrequest.com"><img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg" alt="PRs Welcome"></a>
+  <a href="https://github.com/hashgraph-online/awesome-codex-plugins/pulls"><img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg" alt="PRs Welcome"></a>
   <a href="https://opensource.org/licenses/Apache-2.0"><img src="https://img.shields.io/badge/License-Apache_2.0-blue.svg" alt="License"></a>
   <a href="https://hol.org/registry/plugins"><img src="https://img.shields.io/badge/Browse-Registry-green" alt="Browse Registry"></a>
 </p>