Add 11.0 release notes

[guardrex]

Fixes #36439

Wade, Tom ... Hope you don't mind that I took the liberty of setting this up. There will be Preview 1 Blazor coverage very soon to place, so I was hoping to get this set up and ready to jam 🎷 on now.

UPDATE: The build report now states ...

Line 0: [Warning-PR only] Only lowercase letters, numbers, and hyphens are allowed in filenames.

... so it's 💥 on the period in the filename. However, all of the prior release notes files have a period. Should I change from aspnetcore-11.0.md to aspnetcore-11.md only (no redirect needed for a new file)? If we change them all, then we'll need a lot of redirects.

---

Internal previews

📄 File	🔗 Preview link
aspnetcore/release-notes/aspnetcore-10.0.md	aspnetcore/release-notes/aspnetcore-10.0
aspnetcore/release-notes/aspnetcore-11.md	aspnetcore/release-notes/aspnetcore-11
aspnetcore/toc.yml	aspnetcore/toc

[Copilot]

Pull request overview

This PR establishes the release notes infrastructure for ASP.NET Core 11.0, setting up placeholder content that will be populated as Preview 1 features become available. The changes prepare the documentation repository to accommodate upcoming .NET 11 preview release notes.

Key Changes:

• Added ASP.NET Core 11 entry to the table of contents with proper hierarchy
• Created the main release notes file with standard section structure for Blazor, SignalR, Minimal APIs, OpenAPI, Authentication, and Miscellaneous features
• Set up placeholder include files for Blazor and Blazor Hybrid sections
• Removed temporary "will be updated" text from ASP.NET Core 10 release notes now that it's complete

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
aspnetcore/toc.yml	Adds ASP.NET Core 11 section to "What's new" navigation hierarchy
aspnetcore/release-notes/aspnetcore-11.0.md	Creates main release notes document with metadata, section structure, and placeholder comments for breaking changes
aspnetcore/release-notes/aspnetcore-11/includes/blazor.md	Adds placeholder include file for Blazor preview features
aspnetcore/release-notes/aspnetcore-11/includes/blazor-hybrid.md	Adds placeholder include file for Blazor Hybrid preview features
aspnetcore/release-notes/aspnetcore-10.0.md	Removes "will be updated" text indicating .NET 10 release notes are now complete

[guardrex]

Thanks @wadepickett @tdykstra ... Do you want me to only change the filename for this one new file? ... drop the period from it to make the build happy. Alternatively, would you prefer that I change them all and add all of the needed redirects?

[tdykstra]

Thanks @wadepickett @tdykstra ... Do you want me to only change the filename for this one new file? ... drop the period from it to make the build happy. Alternatively, would you prefer that I change them all and add all of the needed redirects?

Just make the build happy and avoid redirects.