Document Wireless USB considerations

[briansmith]

Wireless USB is, roughly, a way for a device to be connected wirelessly to a system and be treated more-or-less transparently like a wired USB device. The current draft doesn't mention Wireless USB at all so it isn't clear if it has been considered. In particular, it isn't clear if there are any special considerations needed for Wireless USB used in conjunction with WebUSB, especially regarding security.

The current draft only mentions "wireless" once: "While wireless protocols such as Bluetooth". I think contrasting USB with wireless protocols doesn't make sense given that USB devices are also potentially wireless.

Note that the Linux kernel's default behavior is "authorizing all wired USB devices but wireless USB devices are de-authorized by default." according to https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.1-USB-Auth-Default-2. This indicates to me that special considerations for Wireless USB are likely necessary for WebUSB too.