Merge branch 'docs-move-jenkins-migration' into 'master'

Move Jenkins doc to migrations folder

See merge request gitlab-org/gitlab!37288

doc/ci/README.md

@@ -63,7 +63,7 @@ the following documents:
 If you're migrating from another CI/CD tool, check out our handy references:
 
 - [Migrating from CircleCI](migration/circleci.md)
-- [Migrating from Jenkins](jenkins/index.md)
+- [Migrating from Jenkins](migration/jenkins.md)
 
 You can also get started by using one of the
 [`.gitlab-ci.yml` templates](https://gitlab.com/gitlab-org/gitlab-foss/tree/master/lib/gitlab/ci/templates)

doc/ci/migration/circleci.md

 ---
+stage: Verify
+group: Continuous Integration
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers
 comments: false
 type: index, howto
 ---