Readme: Add Black badge

[ruben-iteng]

#Add Black badge

Description

We added Black for code formatting, time to show it around 😎

Fixes # (none)

Checklist

Please read and execute the following:

• My code follows the coding guidelines of this project
• My PR title is following the contribution guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Code of Conduct

By submitting this issue, you agree to follow our Code of Conduct:

• I agree to follow this project's Code of Conduct

[IoannisP-ITENG]

Looks good.
Your commit title & pr title need to be prefix though.
Commit also needs a description.