Add help for C# 11 ref safety errors (#50090)

* Add errors listed in issue

* first edit pass

* final proofread

Give the edits a final proofread

* fix build warnings

* warnings part 2

* Apply suggestions from code review

Co-authored-by: Copilot <[email protected]>

* warnings and feedback

* YAML typo

* Apply suggestions from code review

Co-authored-by: Genevieve Warren <[email protected]>

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Co-authored-by: Copilot <[email protected]>
Co-authored-by: Genevieve Warren <[email protected]>

Author: 3 people

.github/prompts/error-consolidation.md

@@ -68,7 +68,7 @@ Rework the highlighted section so the focus is on how to correct each error. Thi
 
 ## Verify error messages
 
-For every line in this table, verify that the error message associated with this error code matches the verbatim text in CSharpResources.resx. You can find the mapping using ErrorCodes.cs:
+For every line in this list, verify that the error message associated with this error code matches the verbatim text in CSharpResources.resx. You can find the mapping using ErrorCodes.cs:
 
 1. Find that number as a constant in `ErrorCodes.cs`.
 2. Locate the corresponding `data` element in CSharpResources.resx. The `name` atttribute should match the number of the constant.