Update "What's new in ASP.NET Core in .NET 11" for Preview 3

[Copilot]

Adds Preview 3 features from dotnet/core#10344 to the What's New article.

New include files

• zstandard-compression-preview-3.md — Zstandard (zstd) response compression and request decompression support, with code sample and @manandre contributor acknowledgment
• http3-early-request-processing-preview-3.md — Kestrel processes HTTP/3 requests without waiting for control stream/SETTINGS, reducing first-request latency

Updated

• aspnetcore-11.md — Added [!INCLUDE] directives in Miscellaneous section

Excluded per content rules

• Blazor: "Virtualize adapts to variable-height items at runtime" — handled separately by Blazor team
• Bug fixes and community contributors list — not included in What's New

---

Internal previews

📄 File	🔗 Preview link
aspnetcore/release-notes/aspnetcore-11.md	What's new in ASP.NET Core in .NET 11

[wadepickett]

@copilot, rename new include files so that the "preview3" portion of the name is changed to "preview-3" and update links to them. This will help eliminate build warnings that the file name is not a complete word.

[Copilot]

@copilot, rename new include files so that the "preview3" portion of the name is changed to "preview-3" and update links to them. This will help eliminate build warnings that the file name is not a ...

Renamed both files from preview3 to preview-3 and updated the include references in aspnetcore-11.md. See commit c56505a.

[wadepickett]

Approved.

[wadepickett]

@guardrex ,

Added these two features for this PR:
New features:

• Zstandard response compression and request decompression (new feature)
• HTTP/3 starts processing requests earlier (new feature, Kestrel)

I didn't add this one since it was Blazor focused and you like to add your own in your own PR.

• Virtualize adapts to variable-height items at runtime (Blazor — should be skipped

[guardrex]

Thanks, @wadepickett ... It's on #36977.

[wadepickett]

@tdykstra, need your review soon.