Update FAQ

[kompowiec]

EDLC supercapacitors cooperating with a specialized power controller are ideally suited as an energy store for maintaining the power supply. Or use Powerbank.

I'm not sure if it makes sense to include this type of information in this guide, so I did not include it in the end.

[lurch]

Is this already covered by https://github.com/raspberrypi/documentation/blob/master/faqs/README.md#where-is-the-onoff-switch ?

BTW @JamesH65 / @spl237 I guess the "To switch off, if you are in the graphical environment, you can either log out from the main menu, exit to the Bash prompt, or open the terminal." sentence probably needs updating!

[JamesH65]

@lurch Have fixed the FAQ "To switch off" section to current scheme.

As for this PR, I am unsure. It is clearly information that may be useful, but is it enough information? Seems a bit like its teases the reader with something but never fully explains.

[kompowiec]

tbh both parts don't explain why pi there is no protection against card damage. If you think it's worth it, I can give you some solutions, but most of the pages in the documentation do not go in this direction, so I refrained from doing so.

I will not count how many memory cards have been damaged by me in this way because I didn't know what it resulted from.

[aallan]

In light of #1911 and the lack of progress in a long while I'm marking this PR as 7 day closure.

[aallan]

We're deleting the FAQ, see #1913, with the contents distributed throughout the documentation. So closing.