Merge branch 'doc-mj/definition-of-done' into 'master'

Definition of done includes deployed change

See merge request gitlab-org/gitlab-ce!30362

doc/development/contributing/merge_request_workflow.md

@@ -193,6 +193,7 @@ requirements.
 1. [Changelog entry added](../changelog.md), if necessary.
 1. Reviewed by relevant (UX/FE/BE/tech writing) reviewers and all concerns are addressed.
 1. Merged by a project maintainer.
+1. Confirmed to be working in the [Canary stage](https://about.gitlab.com/handbook/engineering/#canary-testing) or on GitLab.com once the contribution is deployed.
 1. Added to the [release post](https://about.gitlab.com/handbook/marketing/blog/release-posts/),
    if relevant.
 1. Added to [the website](https://gitlab.com/gitlab-com/www-gitlab-com/blob/master/data/features.yml), if relevant.