Replace Value Stream Management with Optimize

The group formerly known as Manage:Analytics was briefly re-named
Manage:Value Stream Management before being ultimately re-named
Manage:Optimize. This updates the deprecated references to
Value Stream Management in the documentation to be Optimize.

doc/user/admin_area/analytics/instance_statistics.md

 ---
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/code_review_analytics.md

 ---
 description: "Learn how long your open merge requests have spent in code review, and what distinguishes the longest-running." # Up to ~200 chars long. They will be displayed in Google Search snippets. It may help to write the page intro first, and then reuse it here.
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/index.md

 ---
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/merge_request_analytics.md

 ---
 description: "Merge Request Analytics help you understand the efficiency of your code review process, and the productivity of your team." # Up to ~200 chars long. They will be displayed in Google Search snippets. It may help to write the page intro first, and then reuse it here.
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/productivity_analytics.md

 ---
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/repository_analytics.md

 ---
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/analytics/value_stream_analytics.md

 ---
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/group/contribution_analytics/index.md

 ---
 type: reference
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 # Contribution Analytics **(STARTER)**

doc/user/group/insights/index.md

 ---
 type: reference, howto
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---
 

doc/user/group/issues_analytics/index.md

 ---
 type: reference
 stage: Manage
-group: Value Stream Management
+group: Optimize
 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
 ---