Slight edits after preview

source/handbook/engineering/performance/index.html.md

@@ -160,7 +160,7 @@ revision, new revision, and ref (e.g. tag or branch) name.
 1. Sidekiq updates PostgreSQL
 1. Unicorn can now query PostgreSQL.
-### Availability and Performance Priority Labels
+## Availability and Performance Priority Labels
 {: #performance-labels}
 To clarify the priority of issues that relate to GitLab.com's availability and

source/handbook/infrastructure/index.html.md

@@ -28,6 +28,7 @@ title: "Infrastructure"
 - [GitLab.com architecture](production-architecture/)
 - [Monitoring GitLab.com](monitoring/)
+- [Performance of GitLab.com](/handbook/engineering/performance)
 - [Database team handbook](database/)
 - [Gitaly team handbook](gitaly/)
 - [Production team handbook](production/)