Add FAQ's for external engines?

[richsalz]

In addition to GOST, there's also a TPM engine available at https://sourceforge.net/projects/trousers/files/OpenSSL%20TPM%20Engine/

[levitte]

Suggest an entry?
(our FAQs does need some fleshing out, and probably some cleaning as well)

[richsalz]

Q What other external engines are available?

A We know of one for GOST (at xxxxxurlxxxx) and one for based on TPM (xxxxxxx). Others may be listed in our wiki, at xxxxxx.

[richsalz]

and another one: Look here: https://github.com/MicrochipTech/cryptoauth-openssl-engine

Perhaps "We do not know all of the engines that other projects have released. Here is a list of the ones we know:"

[t-j-h]

The FAQ should just point to the wiki where anyone who has an engine can update the details.
I don't think we should have a partial list of any engines that are not directly included in the distribution in the FAQ.