Readme: Added build badge

README.md

@@ -1,5 +1,7 @@
 # libdatachannel - C/C++ WebRTC network library
 
+[![Build and test](https://github.com/paullouisageneau/libdatachannel/actions/workflows/build-openssl.yml/badge.svg)](https://github.com/paullouisageneau/libdatachannel/actions/workflows/build-openssl.yml)
+
 [![Join the chat at https://gitter.im/libdatachannel/community](https://badges.gitter.im/libdatachannel/community.svg)](https://gitter.im/libdatachannel/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 libdatachannel is a standalone implementation of WebRTC Data Channels, WebRTC Media Transport, and WebSockets in C++17 with C bindings for POSIX platforms (including GNU/Linux, Android, FreeBSD, Apple macOS and iOS) and Microsoft Windows.