Update README.md to change badge links and improve formatting

Signed-off-by: HAHWUL <[email protected]>

README.md

@@ -5,9 +5,8 @@
 <p align="center">
   <a href="https://github.com/hahwul/dalfox/actions/workflows/go.yml"><img src="https://github.com/hahwul/dalfox/actions/workflows/go.yml/badge.svg"></a>
   <a href=""><img src="https://api.codacy.com/project/badge/Grade/17cac7b8d1e849a688577f2bbdd6ecd0"></a>
-  <a href="https://goreportcard.com/report/github.com/hahwul/dalfox"><img src="https://goreportcard.com/badge/github.com/hahwul/dalfox"></a>
-  <a href="https://codecov.io/gh/hahwul/dalfox"><img src="https://codecov.io/gh/hahwul/dalfox/branch/main/graph/badge.svg"/></a>
-  <a href="https://twitter.com/intent/follow?screen_name=hahwul"><img src="https://img.shields.io/twitter/follow/hahwul?style=flat&logo=x"></a>
+  <a href="https://goreportcard.com/report/github.com/hahwul/dalfox/v2"><img src="https://goreportcard.com/badge/github.com/hahwul/dalfox/v2"></a>
+  <a href="https://x.com/intent/follow?screen_name=hahwul"><img src="https://img.shields.io/twitter/follow/hahwul?style=flat&logo=x"></a>
   <a href=""><img src="https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat"></a>
 </p>