docs: update badges

Author: posva

README.md

@@ -5,9 +5,9 @@
 </p>
 <br/>
 <p align="center">
-  <a href="https://npmjs.com/package/pinia"><img src="https://badgen.net/npm/v/pinia" alt="npm package"></a>
-  <a href="https://github.com/vuejs/pinia/actions/workflows/ci.yml"><img src="https://github.com/vuejs/pinia/actions/workflows/ci.yml/badge.svg" alt="build status"></a>
-  <a href="https://codecov.io/gh/vuejs/pinia"><img src="https://codecov.io/gh/vuejs/pinia/graph/badge.svg?token=rU2xxQ6BGH"/></a>
+  <a href="https://npmjs.com/package/pinia"><img src="https://badgen.net/npm/v/pinia/v2" alt="npm package"></a>
+  <a href="https://github.com/vuejs/pinia/actions/workflows/ci.yml"><img src="https://github.com/vuejs/pinia/actions/workflows/ci.yml/badge.svg?branch=v2" alt="build status"></a>
+  <a href="https://codecov.io/gh/vuejs/pinia"><img src="https://codecov.io/gh/vuejs/pinia/branch/v2/graph/badge.svg?token=rU2xxQ6BGH"></a>
 </p>
 <br/>