Merge branch 'docs/mj/architecture-overview' into 'master'

Introduce k8s first approach to adding services

See merge request gitlab-org/gitlab!38172

doc/.vale/gitlab/spelling-exceptions.txt

@@ -298,6 +298,7 @@ OmniAuth
 onboarding
 OpenID
 OpenShift
+Opsgenie
 Packagist
 parallelization
 parallelizations
@@ -382,6 +383,7 @@ reusability
 reverified
 reverifies
 reverify
+RHEL
 rollout
 rollouts
 rsync

doc/development/README.md

@@ -43,6 +43,7 @@ For information on how to install, configure, update, and upgrade your own GitLa
 
 **Must-reads:**
 
+- [Guide on adapting existing and introducing new components](architecture.md#adapting-existing-and-introducing-new-components)
 - [Code review guidelines](code_review.md) for reviewing code and having code reviewed
 - [Database review guidelines](database_review.md) for reviewing database-related changes and complex SQL queries, and having them reviewed
 - [Secure coding guidelines](secure_coding_guidelines.md)