Merge branch 'change-name-to-issue-analytics' into 'master'

Change name to issue analytics

See merge request gitlab-org/gitlab-ee!8489

doc/user/group/issues_analytics/index.md

-# Issues created per month
+# Issues Analytics
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/7478) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.5.