Add a step-by-step guide on how to use Bitcoin Safe for each supported wallet

[design-rrr]

[andreasgriffin]

While this may be too much work, there are resources out there already, which could be linked.

[design-rrr]

Ideally this is to generate contents and improve SEO score fro the website, encourage Bitcoin-Safe download, and give a reason to do it to people that has already a hardware wallet and is looking for guidance.