Use less technical language in the extension

[kkuehlz]

It would be too difficult to use for common people - they don't know what the public key is and why they need to exchange it - it's okay if your tool targets only those who know how it works, but if not, UI need to be improved, tho I can't comment on it much.

Make the extension more friendly to nontechnical people.

Suggested by Yuki2718