docs/unified/novacustom/firmware-update.md: Note that CU doesn't work on Windows

Signed-off-by: Michał Kopeć <michal.kopec@3mdeb.com>

Author: mkopec

docs/unified/novacustom/firmware-update.md

@@ -42,6 +42,8 @@ firmware version is currently installed on your device.
             Capsule updates are only available when Intel ME is HAP-Disabled
             (on unfused platforms) and the AC adapter is connected to the laptop.
 
+            Additionally, Capsule Update is currently not supported on Windows.
+
             See [this Knowledge Base article](../../dasharo-menu-docs/dasharo-system-features.md#intel-management-engine-options)
             for information about disabling the ME, or [Issue #1302](https://github.com/Dasharo/dasharo-issues/issues/1302)
             for more context.