Add aspnetcore.docs copilot to central store

[wadepickett]

Adding the AspNetCore.Docs copilot files to this central store.

The intention is that after these are added, we will work to refactor where needed and from no own local repo changes for AspNetCore.Docs copilot files will have to be edited here then pulled in to the local repo from the central store.

[wadepickett]

@adegeo, I moved the files here per our cconversation. After they are added, we can do following PR's to refactor where needed once we have the system setup for how these will be synced between central store and individual repos.

[Copilot]

Pull request overview

Adds the dotnet/AspNetCore.Docs Copilot instruction set (agents, skills, and repo guidance) into this repo’s central CopilotStore, with the goal of maintaining these prompts in one place and syncing them into the downstream docs repo as needed.

Changes:

• Add ASP.NET Core “What’s New” include-file formatting rules as a reusable skill.
• Add multiple ASP.NET Core doc-focused agents (release-notes → What’s New, breaking-change article creator, issue triage).
• Add repo-level and code-specific Copilot instruction documents for dotnet/AspNetCore.Docs.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
CopilotStore/AspNetCore.Docs/skills/whats-new-include-content-rules/SKILL.md	New skill defining include-file rules; contains a duplicate rule line and a malformed code fence.
CopilotStore/AspNetCore.Docs/copilot-instructions.md	New general instructions; front matter ms.date format conflicts with stated MM/DD/YYYY requirement.
CopilotStore/AspNetCore.Docs/copilot-code-instructions.md	New code-specific instructions; front matter ms.date format conflicts with stated MM/DD/YYYY requirement.
CopilotStore/AspNetCore.Docs/agents/whats-new-from-release-notes.agent.md	New agent; example filename pattern conflicts with the skill’s required -preview-{N} convention.
CopilotStore/AspNetCore.Docs/agents/issue-triage-nonblazor.agent.md	New issue-triage agent prompt.
CopilotStore/AspNetCore.Docs/agents/breakingchange.agent.md	New breaking-change agent prompt; binary-compatibility link points to the wrong anchor.

Comments suppressed due to low confidence (1)

CopilotStore/AspNetCore.Docs/skills/whats-new-include-content-rules/SKILL.md:198

• The closing code fence contains an extra (invisible) character before the backticks, which can break Markdown rendering of the example snippet.

⁣```

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (5)

CopilotStore/AspNetCore.Docs/skills/whats-new-include-content-rules/SKILL.md:193

• The closing code fence in the example include file contains an invisible character (`⁣```), which can break Markdown rendering and cause the rest of the example to be treated as code. Replace it with a plain triple-backtick fence.

⁣```

CopilotStore/AspNetCore.Docs/copilot-instructions.md:81

• This file states that Microsoft Learn links should use relative paths without host/locale, but these links use https://learn.microsoft.com/en-us/.... Use relative /... destinations here to match the rule and avoid conflicting guidance.

* [ ] Follow the [Microsoft Writing Style Guide](https://learn.microsoft.com/en-us/style-guide/welcome/)
  * [ ] Use contractions following the guidance in [Use contractions](https://learn.microsoft.com/en-us/style-guide/word-choice/use-contractions)

CopilotStore/AspNetCore.Docs/copilot-instructions.md:89

• This link also uses an absolute learn.microsoft.com/en-us/... URL even though the earlier guidance says to use relative Learn links. Switch to a relative destination to keep the guidance consistent.

  * [ ] For any new or updated .md file, ensure the standard frontmatter (metadata) is included as specified in [Metadata for Microsoft Learn documentation.](https://learn.microsoft.com/en-us/contribute/content/metadata)

CopilotStore/AspNetCore.Docs/copilot-code-instructions.md:83

• This bullet labels range="5-10" as a syntax error, but earlier in this same document you recommend range/highlight for longer snippets. Consider clarifying that range is valid, but id should be preferred when snippet markers exist (to avoid contradictory guidance).

- [ ] Common Syntax Errors to Avoid:
  - [ ] Using `range="5-10"` instead of `id="snippet_name"`
  - [ ] Using `name="snippet_name"` instead of `id="snippet_name"`

CopilotStore/AspNetCore.Docs/copilot-instructions.md:160

• PR description guidance is inconsistent: this section says to use Fixes #[issue-number], while the What's New include skill requires Fixes dotnet/AspNetCore.Docs#{ISSUE NUMBER} (and documents multi-issue/Related patterns). Pick one convention and update the other location so agents don’t generate different PR descriptions for the same repo.

### 6. PR Description Requirements
* [ ] ALWAYS include "Fixes #[issue-number]" in the PR description, at the first line of the description to link back to the original issue

[wadepickett]

@adegeo, I accepted the copilot suggestions on removing a near duplicate line and updating/fixing the ms.date. It needs a new review/approval to continue. Thanks.