Update multi-key.md

[psacramento-gh]

This seems to be a common misunderstanding among beginners. @sbddesign also considers it relevant, so this is why I'm proposing adding this statement.

[sbddesign]

I like your idea of adding this, but I think it should be worded in passive voice like the other content in the Guide. This is worded more in the active voice ("we would like...")

[GBKS]

While we're at it, we should review how we refer to public and private keys on this page altogether. I think I just spotted an error, as the page states that an application combines private keys into a multisig, while it's really the public keys. Could also be a new PR if you want to keep this one small.

[psacramento-gh]

I would open a new PR for this second correction @GBKS .

[ConorOkus]

Although technically correct when we say "signing a transaction" it doesn't always feel that intuitive to me. Can we include the purpose is to send/spend the funds? You did allude to it by saying "outgoing".

[danielnordh]

Not sure a lot of people think they have to approve incoming transactions.
We could achieve the same clarifying effect just by adding outgoing.

"requiring three of the five co-signers to approve any outgoing transaction."

[psacramento-gh]

How would you guys rephrase @sbddesign version, @ConorOkus and @danielnordh ?

• It is important to remember that the usage of multiple keys is necessary only for signing outgoing transactions, but not for receiving funds. This is a common misunderstanding.