Add brand metadata & update of notes

Author: rudu

openandroidinstaller/assets/configs/Mi439.yaml

@@ -1,5 +1,6 @@
 metadata:
   maintainer: A non (anon)
+  brand: xiaomi
   device_name: Xiaomi Redmi 7A / 8 / 8A / 8A Dual
   is_ab_device: false
   device_code: Mi439
@@ -16,9 +17,7 @@ metadata:
     - olive
     - olivelite
     - olivewood
-  notes: >
-    - If something goes wrong, you can reinstall MiUI here : https://xiaomifirmwareupdater.com
-        
+  notes:
     - Be careful when choosing OrangeFox version, Android 12 & 13 ROM needs OrangeFox version code with `A12`, for example `R11.1_5_A12`. Android 10 & 11 ROM needs OrangeFox version code without `A12` (bellow on the page)
 requirements:
   firmware: MiUI 12.5 (Q)