Create a single signer account example

[tomerweller]

The current custom account example is fairly advanced. I think we can benefit from a "simpler" custom account example.

The simplest viable account I can think of is a single signer account (similar to EOA, externally owned account, on Ethereum). Should we create it as an example?

[kalepail]

I would love to see this. Account abstraction is a huge topic right now and coming up with some examples around multisig or delegated signing would quite very relevant and helpful