Mention adding user to `plugdev` in wiki for WSL

[mck1117]

Running on:

I had to run sudo usermod -a -G plugdev $USER before running the other commands here in order to have the correct permissions for /dev/bus/usb devices.

I'm using STMicroelectronics ST-LINK debug probe for a microcontroller, and this is its relevant rule: ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", MODE="660", GROUP="plugdev", TAG+="uaccess"