Copilot instructions (#2448)

Add the copilot instructions file for use by copilot.

Signed-off-by: Ganesan Ramalingam <grama@microsoft.com>

Author: gramalingam

.github/copilot-instructions.md

@@ -0,0 +1,5 @@
+## Code Standards
+
+### Required Before Each Commit
+- Run `lintrunner -a` before committing any changes to ensure proper code formatting
+- This will run lintrunner on all updated files to maintain consistent style