Assign pages to Code Review group

These pages were all part of the Source Code group, but I believe
they should be reassigned to the new(-ish) Code Review group.

doc/administration/issue_closing_pattern.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments"
 type: reference
 ---

doc/api/merge_request_context_commits.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments"
 type: reference, api
 ---

doc/api/merge_requests.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments"
 type: reference, api
 ---

doc/development/code_intelligence/index.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 ---
 

doc/user/discussions/index.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments"
 type: reference, howto
 ---

doc/user/project/code_intelligence.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments"
 type: reference
 ---

doc/user/project/merge_requests/allow_collaboration.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, howto
 ---

doc/user/project/merge_requests/authorization_for_merge_requests.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: concepts
 ---

doc/user/project/merge_requests/creating_merge_requests.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: howto
 description: "How to create Merge Requests in GitLab."

doc/user/project/merge_requests/getting_started.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: index, reference
 description: "Getting started with Merge Requests."

doc/user/project/merge_requests/index.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: index, reference
 ---

doc/user/project/merge_requests/merge_request_dependencies.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, concepts
 ---

doc/user/project/merge_requests/merge_when_pipeline_succeeds.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, concepts
 ---

doc/user/project/merge_requests/resolve_conflicts.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, concepts
 ---

doc/user/project/merge_requests/revert_changes.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, concepts
 ---

doc/user/project/merge_requests/reviewing_and_managing_merge_requests.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: index, reference
 ---

doc/user/project/merge_requests/work_in_progress_merge_requests.md

 ---
 stage: Create
-group: Source Code
+group: Code Review
 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/#assignments
 type: reference, concepts
 ---