Add notes to work around MacOS App Store logins #474

This work around may work in some situations.

README.md

@@ -389,6 +389,22 @@ There are some considerations when running macOS via Quickemu.
     webdavd](https://gitlab.gnome.org/GNOME/phodav/-/merge_requests/24).
 -   Copy/paste via SPICE agent is **not available on macOS**.
 
+### macOS App Store
+
+If you see *"Your device or computer could not be verified"* when you try to
+login to the App Store, make sure that your wired ethernet device is `en0`. Use
+`ifconfig` in a terminal to verify this.
+
+If the wired ethernet device is not `en0`, then then go to *System Preferences* -> *Network*,
+delete all the network devices and apply the changes. Next, open a terminal and
+run the following:
+
+```bash
+sudo rm /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist
+```
+
+Now reboot, and the App Store should work.
+
 ## Windows 8.1, 10 & 11 Guests
 
 `quickget` can automatically download Windows 8.1, [Windows