Update README.md

add codecov badge

Author: ReneWerner87

.github/README.md

@@ -81,9 +81,9 @@
   <a href="https://goreportcard.com/report/github.com/gofiber/fiber/v3">
     <img src="https://img.shields.io/badge/%F0%9F%93%9D%20goreport-A%2B-75C46B?style=flat-square">
   </a>
-  <a href="https://gocover.io/github.com/gofiber/fiber">
-    <img src="https://img.shields.io/badge/%F0%9F%94%8E%20gocover-97.8%25-75C46B.svg?style=flat-square">
-  </a>
+  <a href="https://codecov.io/gh/gofiber/fiber" > 
+   <img alt="Codecov" src="https://img.shields.io/codecov/c/github/gofiber/fiber?token=3Cr92CwaPQ&style=flat-square&logo=codecov">
+ </a>
   <a href="https://github.com/gofiber/fiber/actions?query=workflow%3ASecurity">
     <img src="https://img.shields.io/github/actions/workflow/status/gofiber/fiber/security.yml?branch=master&label=%F0%9F%94%91%20gosec&style=flat-square&color=75C46B">
   </a>