Move health check docs under user/admin_area/monitoring

[ci skip]

doc/README.md

@@ -63,7 +63,7 @@
 - [Elasticsearch](integration/elasticsearch.md) Enable Elasticsearch.
 - [GitLab GEO](gitlab-geo/README.md) Configure GitLab GEO, a secondary read-only GitLab instance.
 - [GitLab Performance Monitoring](administration/monitoring/performance/introduction.md) Configure GitLab and InfluxDB for measuring performance metrics.
-- [Monitoring uptime](administration/monitoring/health_check.md) Check the server status using the health check endpoint.
+- [Monitoring uptime](user/admin_area/monitoring/health_check.md) Check the server status using the health check endpoint.
 - [Debugging Tips](administration/troubleshooting/debug.md) Tips to debug problems when things go wrong
 - [Sidekiq Troubleshooting](administration/troubleshooting/sidekiq.md) Debug when Sidekiq appears hung and is not processing jobs.
 - [High Availability](administration/high_availability/README.md) Configure multiple servers for scaling or high availability.

doc/monitoring/health_check.md

-This document was moved to [administration/monitoring/health_check](../administration/monitoring/health_check.md).
+This document was moved to [user/admin_area/monitoring/health_check](../user/admin_area/monitoring/health_check.md).