Allow customizing the currency / Add more cryptocurrencies

[bojidar-bg]

(Here from HN)

Was curious if I would have been able to use this tool for some invoices we had to do recently, but apparently there is no support for the DAI stablecoin/cryptocurrency.

Considering there are a lot of cryptocurrencies out there, maybe it would make sense to allow for users to customize the currency field directly?

[dchidindu5]

This is nice idea.
I'm also suggesting that, it should be clearly shown

• fiat currency
• crypto currency
  On separate option boxes