Merge pull request #858 from rgiovanardi/docs-references-readme

Fixing broken link to spec page

README.md

@@ -60,7 +60,7 @@ Participation in the Kubernetes community is governed by the
 [cm]: https://gateway-api.sigs.k8s.io/contributing/community
 [slack]: https://kubernetes.slack.com/messages/sig-network-gateway-api
 [getting-started]: https://gateway-api.sigs.k8s.io/guides/getting-started
-[spec]: https://gateway-api.sigs.k8s.io/references/spec
+[spec]: https://gateway-api.sigs.k8s.io/v1alpha2/references/spec
 [concepts]: https://gateway-api.sigs.k8s.io/concepts/api-overview
 [security-model]: https://gateway-api.sigs.k8s.io/concepts/security-model