Update manage.md

[azarboon]

The following fact should be clearly stated in the doc:

"You can move subscriptions between management groups. Take note that a subscription can only have one parent management group."

[prmerger-automator[bot]]

@azarboon : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[learn-build-service-prod[bot]]

Learn Build status updates of commit ab0296d:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
articles/governance/management-groups/manage.md	:white_check_mark:Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[prmerger-automator[bot]]

PRMerger Results

Issue	Description
GDPR Content(s)	PR references GDPR and must be human reviewed to ensure appropriate guidelines are followed.

[Jak-MS]

@tfitzmac

• Can you review this PR?
• IMPORTANT: When this content is ready to merge, you must add #sign-off in a comment or the approval may get overlooked.

label:"aq-pr-triaged"

@MicrosoftDocs/public-repo-pr-review-team

[tfitzmac]

@azarboon - thanks for this update.

sign-off