[no ci]

docker exec -it gitea-runner-cache-server rm -rf /runner-cache/*

README.md

@@ -18,6 +18,10 @@ docker run -d --name gitea-runner-cache-server \
 docker logs gitea-runner-cache-server
 ```
 
+```
+docker exec -it gitea-runner-cache-server rm -rf /runner-cache/*
+```
+
 ## Gitea Runner
 - https://github.com/vegardit/docker-gitea-act-runner#additional-environment-variables