Update the manager metadata from Celeste to Precious

[msewaweru]

This pull request updates the manager metadata field across multiple documentation files in the Microsoft Graph PowerShell SDK repository. The change replaces CelesteDG with mwongerapk as the manager in all affected files. Below is a summary of the changes grouped by the type of documentation.

[learn-build-service-prod]

Learn Build status updates of commit 914bd75:

✅ Validation status: passed

File	Status	Preview URL	Details
microsoftgraph/docs-conceptual/app-only.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/authentication-commands.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/azuread-msoline-cmdlet-map.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/find-mg-graph-command.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/find-mg-graph-permission.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/get-started.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/how-to-assign-microsoft-entra-roles-in-pim.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/how-to-grant-revoke-api-permissions.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/installation.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/migration-steps.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/navigating.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/overview.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/troubleshooting.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/tutorial-entitlement-management.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)
microsoftgraph/docs-conceptual/use-query-parameters.md	✅Succeeded	View (graph-powershell-1.0 || graph-powershell-beta)

For more details, please refer to the build report.

[omondiatieno]

LGTM!