Updates around config files

[gewarren]

Related to #7979. Updates remarks that refer to app.config files, to note that they are specific to .NET Framework apps.

[opbld30]

Docs Build status updates of commit 82bc27a:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/Microsoft.CSharp/CSharpCodeProvider.xml	✅Succeeded	View
xml/Microsoft.VisualBasic.Logging/FileLogTraceListener.xml	✅Succeeded	View
xml/Microsoft.VisualBasic/VBCodeProvider.xml	✅Succeeded	View
xml/System.ComponentModel.DataAnnotations/ValidationContext.xml	✅Succeeded	View
xml/System.ComponentModel/TypeConverter.xml	✅Succeeded	View
xml/System.Configuration/ConfigurationCollectionAttribute.xml	✅Succeeded	View
xml/System.Resources/ResourceManager.xml	✅Succeeded	View
xml/System.Runtime/GCSettings.xml	✅Succeeded	View
xml/System.Threading/Thread.xml	✅Succeeded	View
xml/System/AppContext.xml	✅Succeeded	View
xml/System/String.xml	✅Succeeded	View
xml/System/Uri.xml	✅Succeeded	View
xml/ns-System.Transactions.Configuration.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

[BillWagner]

This LGTM @gewarren

Once you and the product team are happy, you can .