Update user/group/clusters/index.md

Fix version history structure

doc/user/group/clusters/index.md

@@ -33,7 +33,7 @@ installation, such as an Ingress controller.
 ## RBAC compatibility
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/29398) in GitLab 11.4.
-> - [Project namespace restriction](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/51716) was introduced in GitLab 11.5.
+> - Project namespace restriction was [introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/51716) in GitLab 11.5.
 
 For each project under a group with a Kubernetes cluster, GitLab creates a restricted
 service account with [`edit` privileges](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#user-facing-roles)
@@ -49,7 +49,7 @@ to the project, provided the cluster is not disabled.
 
 ## Multiple Kubernetes clusters
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/35094) in GitLab Free 13.2.
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/35094) in GitLab 13.2.
 
 You can associate more than one Kubernetes cluster to your group, and maintain different clusters
 for different environments, such as development, staging, and production.