Fix the CI badge

Author: jessebraham

README.md

@@ -1,6 +1,6 @@
 # esp-hal
 
-![GitHub Workflow Status](https://img.shields.io/github/workflow/status/esp-rs/esp-hal/CI?label=CI&logo=github&style=flat-square)
+![GitHub Workflow Status](https://img.shields.io/github/actions/workflow/status/esp-rs/esp-hal/ci.yml?label=CI&logo=github&style=flat-square)
 ![MIT/Apache-2.0 licensed](https://img.shields.io/badge/license-MIT%2FApache--2.0-blue?style=flat-square)
 [![Matrix](https://img.shields.io/matrix/esp-rs:matrix.org?label=join%20matrix&color=BEC5C9&logo=matrix&style=flat-square)](https://matrix.to/#/#esp-rs:matrix.org)