Doc consistency edits for user/infrastructure

doc/user/infrastructure/clusters/manage/management_project_applications/elasticstack.md

@@ -4,7 +4,7 @@ group: Monitor
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
 ---
 
-# Install Elastic Stack with a cluster management project
+# Install Elastic Stack with a cluster management project **(FREE)**
 
 > [Introduced](https://gitlab.com/gitlab-org/project-templates/cluster-management/-/merge_requests/5) in GitLab 14.0.
 

doc/user/infrastructure/clusters/manage/management_project_applications/prometheus.md

@@ -4,7 +4,7 @@ group: Monitor
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
 ---
 
-# Install Prometheus with a cluster management project
+# Install Prometheus with a cluster management project **(FREE)**
 
 > [Introduced](https://gitlab.com/gitlab-org/project-templates/cluster-management/-/merge_requests/5) in GitLab 14.0.
 

doc/user/infrastructure/clusters/manage/management_project_applications/sentry.md

@@ -4,7 +4,7 @@ group: Monitor
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
 ---
 
-# Install Sentry with a cluster management project
+# Install Sentry with a cluster management project **(FREE)**
 
 > [Introduced](https://gitlab.com/gitlab-org/project-templates/cluster-management/-/merge_requests/5) in GitLab 14.0.