add case-insensitive note

[marsen]

note that the name of the configuration section is case-insensitive.

Summary

Added this note to provide more information to developers

Fixes #Issue_Number (if available)

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[opbld33]

Docs Build status updates of commit 2cd06f9:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/Microsoft.Extensions.Configuration/ConfigurationManager.xml	✅Succeeded	View

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[gewarren]

I think that info should rather go in the remarks?

[gewarren]

Suggested change

	<remarks>To be added.</remarks>
	<remarks>The name of the configuration section is case-insensitive.</remarks>

[opbld30]

Docs Build status updates of commit 280f5e8:

⚠️ Validation status: warnings

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[opbld34]

Docs Build status updates of commit 34643e1:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/Microsoft.Extensions.Configuration/ConfigurationManager.xml	✅Succeeded	View

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the docs.microsoft.com contributor guides
• Post your question in the Docs support channel

[gewarren]

Thank you @marsen.