Merge branch 'jej-fix-doc-performance-link-to-monitoring' into 'master'

Fix link from doc/development/performance.md to 'Performance Monitoring'

Another link fix!

Fixes link from [doc/development/performance.md](doc/development/performance.md) to 'Gitlab Performance Monitoring'

See merge request !8155

doc/development/performance.md

@@ -37,7 +37,7 @@ graphs/dashboards.
 GitLab provides built-in tools to aid the process of improving performance:
 * [Sherlock](profiling.md#sherlock)
-* [GitLab Performance Monitoring](../administration/monitoring/performance/monitoring.md)
+* [GitLab Performance Monitoring](../administration/monitoring/performance/introduction.md)
 * [Request Profiling](../administration/monitoring/performance/request_profiling.md)
 GitLab employees can use GitLab.com's performance monitoring systems located at