checkupdates-aur: add page (#7775)

pages/linux/checkupdates-aur.md

@@ -0,0 +1,16 @@
+# checkupdates-aur
+
+> Tool to check pending updates from the Arch User Repository (AUR).
+> More information: <https://metacpan.org/dist/OS-CheckUpdates-AUR>.
+
+- List pending updates for AUR packages:
+
+`checkupdates-aur`
+
+- List pending updates for AUR packages in debug mode:
+
+`CHECKUPDATES_DEBUG=1 checkupdates-aur`
+
+- Display help:
+
+`checkupdates-aur --help`