Add the close popup information

[bijington]

This PR also involves a restructuring to split out some Popup related bits

[learn-build-service-prod]

Learn Build status updates of commit 6d998cc:

❌ Validation status: errors

Please follow instructions here which may help to resolve issue.

File	Status	Preview URL	Details
docs/maui/views/popup/overview.md	❌Error		Details
docs/maui/views/index.md	⚠️Warning		Details
docs/maui/views/popup/popup-service.md	⚠️Warning		Details

docs/maui/views/popup/overview.md

• Line 25, Column 1: [Error: include-not-found - See documentation] Invalid include link: '../includes/xaml-usage.md'.
• Line 2, Column 8: [Warning: duplicate-titles - See documentation] Title 'Popup - .NET MAUI Community Toolkit - Community Toolkits for .NET' is duplicated in: 'maui/views/popup/overview.md(2,8), maui/views/popup/popup-service.md(2,8)'. Titles must be unique within a docset.
• Line 13, Column 86: [Warning: file-not-found - See documentation] Invalid file link: '../alerts/toast.md'.
• Line 13, Column 118: [Warning: file-not-found - See documentation] Invalid file link: '../alerts/snackbar.md'.

docs/maui/views/index.md

• Line 29, Column 3: [Warning: file-not-found - See documentation] Invalid file link: 'Popup.md'.

docs/maui/views/popup/popup-service.md

• Line 2, Column 8: [Warning: duplicate-titles - See documentation] Title 'Popup - .NET MAUI Community Toolkit - Community Toolkits for .NET' is duplicated in: 'maui/views/popup/overview.md(2,8), maui/views/popup/popup-service.md(2,8)'. Titles must be unique within a docset.
• Line 16, Column 126: [Warning: bookmark-not-found - See documentation] Cannot find bookmark '#defining-your-popup' in 'maui/views/popup/popup-service.md'.
• Line 132, Column 104: [Warning: file-not-found - See documentation] Invalid file link: './Popup.md'.

For more details, please refer to the build report.

Note: Your PR may contain errors or warnings or suggestions unrelated to the files you changed. This happens when external dependencies like GitHub alias, Microsoft alias, cross repo links are updated. Please use these instructions to resolve them.

For any questions, please:

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

[learn-build-service-prod]

Learn Build status updates of commit 847bbc4:

⚠️ Validation status: warnings

File	Status	Preview URL	Details
docs/maui/views/index.md	⚠️Warning	View	Details
docs/maui/views/Popup.md	⚠️Warning	n/a (file deleted or renamed)	Details
docs/maui/TOC.yml	✅Succeeded	View
docs/maui/views/popup/overview.md	✅Succeeded	View
docs/maui/views/popup/popup-service.md	✅Succeeded	View

docs/maui/views/index.md

• Line 29, Column 3: [Warning: file-not-found - See documentation] Invalid file link: 'Popup.md'.

docs/maui/views/Popup.md

• [Warning: file-not-redirected - See documentation] File docs/maui/views/Popup.md with URL /dotnet/communitytoolkit/maui/views/popup was deleted without redirection. To avoid broken links, add a redirection.

For more details, please refer to the build report.

Note: Your PR may contain errors or warnings or suggestions unrelated to the files you changed. This happens when external dependencies like GitHub alias, Microsoft alias, cross repo links are updated. Please use these instructions to resolve them.

For any questions, please:

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

[learn-build-service-prod]

Learn Build status updates of commit 7edc800:

⚠️ Validation status: warnings

File	Status	Preview URL	Details
docs/maui/views/index.md	⚠️Warning	View	Details
docs/maui/views/Popup.md	⚠️Warning	n/a (file deleted or renamed)	Details
docs/maui/TOC.yml	✅Succeeded	View
docs/maui/views/popup/popup-service.md	✅Succeeded	View
docs/maui/views/popup/Popup.md	✅Succeeded	View

docs/maui/views/index.md

• Line 29, Column 3: [Warning: file-not-found - See documentation] Invalid file link: 'Popup.md'.

docs/maui/views/Popup.md

• [Warning: file-not-redirected - See documentation] File docs/maui/views/Popup.md with URL /dotnet/communitytoolkit/maui/views/popup was deleted without redirection. To avoid broken links, add a redirection.

For more details, please refer to the build report.

Note: Your PR may contain errors or warnings or suggestions unrelated to the files you changed. This happens when external dependencies like GitHub alias, Microsoft alias, cross repo links are updated. Please use these instructions to resolve them.

For any questions, please:

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

[learn-build-service-prod]

Learn Build status updates of commit 9880714:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/maui/TOC.yml	✅Succeeded	View
docs/maui/views/popup-service.md	✅Succeeded	View
docs/maui/views/Popup.md	✅Succeeded	View

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

[learn-build-service-prod]

Learn Build status updates of commit 6468d9e:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/maui/TOC.yml	✅Succeeded	View
docs/maui/views/popup-service.md	✅Succeeded	View
docs/maui/views/Popup.md	✅Succeeded	View

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