chore: update initramfs args example (#763)

system_files/desktop/shared/etc/bazzite/initramfs/args.d/00-example.conf

@@ -7,6 +7,12 @@
 # config files for dracut into /etc/dracut.conf.d/ and trigger an initramfs
 # rebuild using "sudo touch /etc/bazzite/initramfs/rebuild" which
 # will rebuild the initramfs on next boot using bazzite-hardware-setup.
+# Documentation: https://universal-blue.discourse.group/docs?topic=399
+#
+# NOTE: If you need to add files to initramfs (like modprobe files),
+# please add them to a .conf file in /etc/dracut.conf.d/
+# with the line (spaces before and after paths are important!)
+# install_items+=" /path/to/file1 /path/to/file2 "
 #
 # Multiline Example:
 #--arg="--add-drivers"