Add the status badge for cross-zoo.yml in the README.
[](https://github.com/haproxy/haproxy/actions/workflows/aws-lc.yml)
[](https://github.com/haproxy/haproxy/actions/workflows/illumos.yml)
[](https://github.com/haproxy/haproxy/actions/workflows/netbsd.yml)
+[](https://github.com/haproxy/haproxy/actions/workflows/cross-zoo.yml)
[](https://cirrus-ci.com/github/haproxy/haproxy/)
[](https://github.com/haproxy/haproxy/actions/workflows/vtest.yml)