Allow user input fingerprint.json file

Instead of having a fixed fingerprint file, it would be more convenient to use a flag to parse the fingerprint.json file.

The format for the json could be similar to the other Go-based tools to ensure ease and convenience to managing a single format.

Hi @sumgr0,

Thank you for raising this issue! This seems to be a highly convenient implementation, as you mentioned. I will work on this as soon as possible.

Thanks, @TheBinitGhimire