FAQ: Add sentence about Tails on handheld devices

Originally created by @BitingBird on #9643 (Redmine)

We get the question a lot. We should edit https://tails.boum.org/doc/about/requirements to make a note specifying that

Tails doesn't work on smartphones and tables yet. 

On the FAQ:

Does Tails work on smartphones or tablets?

Not yet. Tails requires an x86 compatible processor: While Mac computers are IBM PC compatible since 2006, most smartphones and tablets contain ARM processors. But we are working on it!"

and then link to #6064 (closed) ticket and blueprint.

Related issues

• Related to #6064 (closed)
• Blocks #13423 (closed)