Fix typo

[changeworld]

Github -> GitHub

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

Learn Build status updates of commit cdc0157:

:warning: Validation status: warnings

File	Status	Preview URL	Details
docs-ref-services/latest/dns-mgmt-index.md	:warning:Warning	View (azure-node-latest)	Details

docs-ref-services/latest/dns-mgmt-index.md

• Line 0, Column 0: [Warning: h1-missing - See documentation] H1 is required. Use a single hash (#) followed by a space to create your top-level heading.
• Line 1, Column 1: [Warning: title-missing - See documentation] Missing required attribute: 'title'. Add a title string to show in search engine results.
• Line 1, Column 1: [Warning: ms-prod-or-service-missing - See documentation] One of the following attributes is required: 'ms.prod', 'ms.service'. Use ms.prod for on-premise products, or ms.service for cloud services.
• Line 1, Column 1: [Suggestion: description-missing - See documentation] Missing required attribute: 'description'.
• Line 1, Column 1: [Suggestion: ms-topic-missing - See documentation] Missing required attribute: 'ms.topic'.

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