Fix typo in instructions (#8354)

Fix typo (intructions -> instructions)

Author: hairihou

docs/copilot/copilot-customization.md

@@ -174,7 +174,7 @@ The following example demonstrates custom instructions for code generation:
     ---
     # Project coding standards for TypeScript and React
 
-    Apply the [general coding guidelines](./general-coding.intructions.md) to all code.
+    Apply the [general coding guidelines](./general-coding.instructions.md) to all code.
 
     ## TypeScript Guidelines
     - Use TypeScript for all new code