Add simple start-of-readme bulleted list of resources, and banners

[timlnx]

Look at https://raw.githubusercontent.com/PyCQA/bandit/refs/heads/main/README.rst

That's got a great abbreviated little list of stuff

* Free software: Apache license
* Documentation: https://bandit.readthedocs.io/en/latest/
* Source: https://github.com/PyCQA/bandit
* Bugs: https://github.com/PyCQA/bandit/issues
* Contributing: https://github.com/PyCQA/bandit/blob/main/CONTRIBUTING.md

Add those as a simple list at the top of the README.

Also probably more banners. I bet we can add more banners