docs: update faq to mention apt for dependencies

[rokroskar]

This PR adds information about using apt to install dependencies to the FAQ.

[agjohnson]

Good call, thanks for the addition! This is a great spot to call out to apt installation as another option for missing dependencies.

[agjohnson]

This would be great as a link to the section in config-file for apt install configuration option. It should be addressable using the auto section reference syntax

[astrojuanlu]

Thanks for this pull request! Can we use this opportunity to reword the sentence that confused you?

We can't support installing random C binaries on our system, so there is another way to fix these imports.

[rokroskar]

Can we use this opportunity to reword the sentence that confused you?

Ha, indeed I actually started with that sentence. But then I realized that what brought me there was the link from the section above. The part with the controversial sentence is specifically talking about mocking when install of libraries is not possible - and the only way I saw to sneak in a mention of apt was to link back to the section above... which then results in a circular dependency 🤷 But I will try to adapt the wording there to alleviate the confusion a bit

[rokroskar]

@astrojuanlu and @agjohnson thanks for your comments - I've tried to address them in 8895b91

[astrojuanlu]

Thanks a lot!