Update shortTitle for use-custom-instructions article (#60731)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: crwaters16 <78226508+crwaters16@users.noreply.github.com>
Co-authored-by: Sarita Iyer <66540150+saritai@users.noreply.github.com>

Author: 3 people

content/copilot/tutorials/use-custom-instructions.md

@@ -1,6 +1,6 @@
 ---
 title: Using custom instructions to unlock the power of Copilot code review
-shortTitle: Use custom instructions
+shortTitle: Customize code review
 intro: 'Learn how to write effective custom instructions that help {% data variables.product.prodname_copilot %} provide more relevant and actionable code reviews.'
 versions:
   feature: copilot