Add ASP.NET Core release notes for .NET 10 Preview 5

[Copilot]

This PR adds the ASP.NET Core release notes for .NET 10 Preview 5 based on the content provided in dotnet/AspNetCore.Docs#35473.

Changes Made

• Created aspnetcore.md for .NET 10 Preview 5 with comprehensive release notes covering:

  • Custom Security Descriptors for HTTP.sys Request Queues - New feature allowing granular access control using RequestQueueSecurityDescriptor property
  • Validation in Minimal APIs - Improvements and fixes to the validation generator introduced in Preview 4
  • OpenAPI 3.1 support - Upgrade to OpenAPI.NET v2.0.0-preview18
  • OpenAPI metadata from XML doc comments - Extended support for extracting metadata from <returns> and <response> XML tags
  • Router NotFoundPage parameter - New Blazor feature for handling NotFound responses with typed pages

• Updated main README.md to include the Preview 5 link in proper chronological order

Content Source

All content is based on the official feature descriptions provided by the ASP.NET Core development team in the referenced issue comments, ensuring accuracy and consistency with the official documentation.

The release notes follow the established format and structure of previous preview releases for consistency.

Fixes #9924.

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[danroth27]

Generate and add the list of contributors for milestone 10.0-preview5:

• Get the list of contributors for milestone: gh search prs --milestone {milestone} --merged --label community-contribution --json author --limit 1000 > authors.json
• Filter the list of contributors to unique external contributors that aren't infrastructure bots and that don't work at Microsoft on the .NET team.
• Sort the list of contributors by author login name alphabetically.
• Generate the contributors list linking to their merged PRs in the dotnet/aspnetcore repo for the milestone: - [@{author.login}](https://github.com/dotnet/aspnetcore/pulls?q=is%3Apr+is%3Amerged+milestone%3A{milestone}+author%3A{author.login})

[Copilot]

Generate and add the list of contributors for milestone 10.0-preview5:

• Get the list of contributors for milestone: `gh search prs --milestone {milestone} --merged --label community-contribution -...

Added the contributors list for milestone 10.0-preview5. Found 4 external community contributors (filtered out Microsoft employees and bots), sorted alphabetically with links to their merged PRs. Commit e99e60d.

[danroth27]

Let's include contributor am11 in the contributors list. They are a member of the .NET org on GitHub, but they aren't at Microsoft.

[Copilot]

Let's include contributor am11 in the contributors list. They are a member of the .NET org on GitHub, but they aren't at Microsoft.

Added am11 to the contributors list in alphabetical order. Commit 89b9e81.

[Copilot]

Pull Request Overview

Adds detailed ASP.NET Core release notes for .NET 10 Preview 5, covering new security, validation, OpenAPI, Blazor routing, and observability features.

• Introduces a new aspnetcore.md file with comprehensive release notes
• Updates table of contents and feature sections (HTTP.sys, Minimal APIs, OpenAPI, Blazor)
• (In metadata) README updated to include Preview 5 link in order

Comments suppressed due to low confidence (2)

release-notes/10.0/preview/preview5/aspnetcore.md:129

• [nitpick] The nested list under Circuit lifecycle tracing mixes indent levels; align bullet indentation consistently (e.g., four spaces) for better readability.

  - Tags: `aspnetcore.components.circuit.id`

release-notes/10.0/preview/preview5/aspnetcore.md:85

• In Razor syntax, code expressions should be prefixed with '@'. Change NotFoundPage="typeof(Pages.NotFound)" to NotFoundPage="@typeof(Pages.NotFound)" for correct parsing.

<Router AppAssembly="@typeof(Program).Assembly" NotFoundPage="typeof(Pages.NotFound)">