update README.md

Rain Liu · Rain Liu · commit 57bb1affe2e7 · 2021-10-09T23:38:28.000-07:00
diff --git a/README.md b/README.md
@@ -26,5 +26,5 @@
  </a>
 </p>
 <p align="center">
- A pure Rust implementation of SDP. Rewrite <a href="https://github.com/pion/sdp/releases/tag/v2.4.0">Pion</a> SDP in Rust
+ A pure Rust implementation of SDP. Rewrite <a href="https://github.com/pion/sdp/releases/tag/v3.0.4">Pion</a> SDP in Rust
 </p>
