Add helpful note from arch wiki to secure boot setup instructions (#360)

* Add helpful note from arch wiki to secure boot setup instructions

Source: https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot#Creating_and_enrolling_keys

* Always add OEM certs

Updated instructions for setting up sbctl to include OEM firmware's built-in keys for certain PCs.

Author: derdilla

src/content/docs/configuration/secure_boot_setup.mdx

@@ -62,7 +62,8 @@ Created Owner UUID a9fbbdb7-a05f-48d5-b63a-08c5df45ee70
 Creating secure boot keys...✔
 Secure boot keys created!
 
-sudo sbctl enroll-keys --microsoft # Enroll your keys with Microsoft's keys
+# Enroll your keys with Microsoft's and the OEM firmware's built-in keys
+sudo sbctl enroll-keys --microsoft --firmware-builtin
 Enrolling keys to EFI variables...✔
 Enrolled keys to the EFI variables!