Add assisted by Claude credit

Author: vfaraji89

instructions/context-engineering.instructions.md

@@ -41,3 +41,7 @@ Principles for helping GitHub Copilot understand your codebase and provide bette
 - **Missing context**: Open the relevant files in tabs, or explicitly paste code snippets.
 - **Stale suggestions**: Copilot may not see recent changes. Re-open files or restart the session.
 - **Generic answers**: Be more specific. Add constraints, mention frameworks, reference existing code.
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+---
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+*Assisted by [Claude](https://claude.ai)*