Quick fix to News Search headers and tutorial

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

Learn Build status updates of commit 78002aa:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
bing-docs/bing-news-search/reference/headers.md	:white_check_mark:Succeeded	View
bing-docs/bing-news-search/tutorial/bing-news-search-single-page-app.md	:white_check_mark:Succeeded	View

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