doc: Shorten phrasing.
|After installing Tails (both [[manually|manual_usb_installation]] and [[using|
|the USB installer|usb_installer]]), you will end up with a USB stick in a weird|
|state, and you might want to reset it, and use it for something else.|
|To erase Tails from a USB stick, and use it for something else, you have to|
|**The content of the USB stick will be lost in the operation,** but an attacker|
|might still be able to tell that Tails was installed on the USB stick using|