Add docs for new token minting functionality in Wasp

[Dr-Electron]

Describe the solution you'd like

As we found out in #1565, we should add another how-to to the wasp docs to document the new token minting process introduced here

With this change newly minted tokens are automatically registered and available as ERC20.

So where you currently have to implement both the functions explained here and here you will have to just call the createNativeTokenFoundry function from the ISCAccounts magic contract