docs: set page title for maintaining AUR packages user story (#22690)

Co-authored-by: Rhys Arkins <rhys@arkins.net>

docs/usage/user-stories/maintaining-aur-packages-with-renovate.md

+---
+title: Maintaining AUR packages with Renovate
+---
+
 <!-- hide table of contents in navigation sidebar -->
 <style>
 .md-nav--primary .md-nav__link[for=__toc] ~ .md-nav {