Add help for C# 11 ref safety errors

[BillWagner]

Fixes #49598

Some of these had already been covered. To manage the scope, split one existing file into two.

---

Internal previews

📄 File	🔗 Preview link
.github/prompts/error-consolidation.md	Copilot prompts to consolidate error codes.
docs/csharp/language-reference/compiler-messages/ref-modifiers-errors.md	Errors and warnings associated with reference parameters, variables, and returns
docs/csharp/language-reference/compiler-messages/ref-safety-errors.md	Errors and warnings related to ref safety
docs/csharp/language-reference/toc.yml	docs/csharp/language-reference/toc
docs/csharp/misc/sorry-we-don-t-have-specifics-on-this-csharp-error.md	Sorry, we don't have specifics on this C# error

[Copilot]

Pull request overview

This PR adds comprehensive documentation for C# 11 ref safety errors by splitting the existing ref-modifiers-errors.md file into two focused documents. The new ref-safety-errors.md file specifically covers ref safety violations related to escape scopes, ref assignments, and struct member restrictions, while ref-modifiers-errors.md now focuses solely on reference parameter modifier usage errors.

Key changes:

• Created ref-safety-errors.md to document 29 error codes related to ref safety violations (CS8166-CS9097 range)
• Reorganized ref-modifiers-errors.md to remove ref safety content and add scoped/unscoped parameter errors
• Updated TOC to include the new ref safety errors section with appropriate error code mappings

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
docs/csharp/language-reference/compiler-messages/ref-safety-errors.md	New file documenting ref safety errors organized into four thematic sections: returning references with incompatible scopes, ref assignments, escape scope violations, and struct member restrictions
docs/csharp/language-reference/compiler-messages/ref-modifiers-errors.md	Updated to remove ref safety content (moved to new file) and add scoped/unscoped parameter error documentation with corrected frontmatter
docs/csharp/language-reference/toc.yml	Added new "Ref safety" entry and updated "Reference parameters" entry to reflect the error code reorganization
docs/csharp/misc/sorry-we-don-t-have-specifics-on-this-csharp-error.md	Removed 34 error codes that are now documented in the new ref safety and updated ref modifiers files
.github/prompts/error-consolidation.md	Minor wording correction changing "table" to "list" for clarity

Comments suppressed due to low confidence (1)

docs/csharp/language-reference/compiler-messages/ref-modifiers-errors.md:63

• Missing CS8977 and CS8986 from the f1_keywords section. CS8977 appears in helpviewer_keywords (line 93) and CS8986 is documented in the article (line 151), but both are missing from f1_keywords. Both sections should include all documented error codes.

f1_keywords:
  - "CS0192"
  - "CS0199"
  - "CS0206"
  - "CS0631"
  - "CS0767"
  - "CS1510"
  - "CS1605"
  - "CS1623"
  - "CS1649"
  - "CS1651"
  - "CS1655"
  - "CS1657"
  - "CS1741"
  - "CS1939"
  - "CS1988"
  - "CS7084"
  - "CS8196"
  - "CS8325"
  - "CS8326"
  - "CS8327"
  - "CS8329"
  - "CS8330"
  - "CS8331"
  - "CS8332"
  - "CS8337"
  - "CS8338"
  - "CS8373"
  - "CS8388"
  - "CS8987"
  - "CS9061"
  - "CS9062"
  - "CS9063"
  - "CS9065"
  - "CS9066"
  - "CS9072"
  - "CS9073"
  - "CS9074"
  - "CS9101"
  - "CS9102"
  - "CS9104"
  - "CS9104"
  - "CS9104"
  - "CS9104"
  - "CS9104"
  - "CS9104"
  - "CS9104"
  - "CS9190"
  - "CS9191"
  - "CS9192"
  - "CS9193"
  - "CS9195"
  - "CS9196"
  - "CS9197"
  - "CS9198"
  - "CS9199"
  - "CS9200"
  - "CS9201"
  - "CS9205"
  - "CS9265"