Merge branch 'docs-add-redirect-explore' into 'master'

Docs: Add redirect for obsolete explore-gitlab university page

See merge request gitlab-org/gitlab!38224

doc/university/training/topics/explore_gitlab.md

 ---
-comments: false
+redirect_to: '../../../gitlab-basics/README.md'
 ---
 
-# Explore GitLab projects
-
-- Dashboard
-- User Preferences
-- Issues
-- Milestones and Labels
-- Manage project members
-- Project settings
+This document was moved to [another location](../../../gitlab-basics/README.md).