Improve annotations documentation and rule references

[meziantou]

Why

Users configuring annotation-based rules reported that it was not obvious that Meziantou.Analyzer.Annotations is a separate package dependency. The docs now make that requirement explicit directly from each impacted rule page.

What changed

• Updated rule docs that use annotation attributes to clearly state the dependency and link to the annotations project README:
  • MA0003, MA0011, MA0042, MA0045, MA0075, MA0076, MA0124, MA0139, MA0185
• Expanded src/Meziantou.Analyzer.Annotations/README.md to serve as the central reference with:
  • install guidance (dotnet add package Meziantou.Analyzer.Annotations)
  • source-copy guidance (namespace/type-name matching, public or internal)
  • a table mapping annotation attributes to related rules
• Updated .github/copilot-instructions.md so changes under src/Meziantou.Analyzer.Annotations require:
  • updating the annotations README
  • bumping the annotations package version
• Bumped src/Meziantou.Analyzer.Annotations/Meziantou.Analyzer.Annotations.csproj version to 1.3.1.

Notes

This keeps documentation discoverability high from rule pages while using the package README as the single source of truth for annotation usage.