Refactor: Add Banner

[mali-git]

What does this PR do?

This PR adds the Modalities banner to the README.

General Changes

• Upload banner
• Integrate banner into README

Breaking Changes

• None

Checklist before submitting final PR

• [x] My PR is minimal and addresses one issue in isolation
• [x] I have merged the latest version of the target branch into this feature branch
• [x] I have reviewed my own code w.r.t. correct implementation, missing type hints, proper documentation, etc.
• [x] I have run a sample config for model training
• [x] I have checked that all tests run through (python tests/tests.py)