[EXTERNAL] Update docs blockchain/time-is-money

[abdotop]

I'd like to report an inconsistency in the project requirements and test implementation:

The README instructions state:
"Add a function addPayedArtist() that takes as parameters a string and an address to register an artist to the festival."

However, the tests are only using the address parameter and not the name (string) parameter when calling this function.

This discrepancy is causing confusion and leading to implementation errors. It would be helpful to either:

1. Update the tests to include both the name and address parameters, or
2. Modify the README to reflect that only the address is required for the addPayedArtist() function.

Clarifying this point will ensure that the implementation matches the intended requirements and resolves the current test failures.