[Suggestion] Better uninstall instructions in read me

[Aces-and-Jacks]

So I was uninstalling and had to look around till someone said you needed to reboot after making the uninstall file.

So basically for better understanding instead of "To uninstall NickelMenu, just create a new file named uninstall in .adds/nm/, or trigger the failsafe mechanism by immediately powering off the Kobo after it starts booting."

change to

"To uninstall NickelMenu, just create a new file named uninstall in .adds/nm/ and reboot, or trigger the failsafe mechanism by immediately powering off the Kobo after it starts booting."