Doc: Clarify W3CLogger service registration and default log location (#33592)

[SkyDevLab]

Fixes #33592

Summary of Changes

• Clarified that enabling W3CLogger requires registering the required services using AddW3CLogging before adding the middleware via UseW3CLogging in the request processing pipeline. Previously, only UseW3CLogging was shown in the "Enable W3CLogger" snippet, which leads to InvalidOperationException at startup if AddW3CLogging was omitted.
• Documented the default log output location (./logs/ relative to the content root directory) and filename format (w3clog- prefix).
• Documented the configuration options supported by W3CLoggerOptions (such as LogDirectory, FileName, FileSizeLimit, FlushInterval, and RetainedFileCountLimit).
• Updated ms.date.

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Build report

[SkyDevLab]

Thanks @guardrex! Updated to apply all suggestions.

[SkyDevLab]

Thank you @guardrex! I have removed author and ms.author from the metadata per your feedback.

[Copilot]

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[Copilot]

🟢 Approval recommended

The guidance and API references accurately address the reported documentation gap.

0 open findings

🧠 Review effort: Balanced