First OSS commit

The initial release of the In-Context Explainability 360 toolkit, an open-source Python toolkit to perform source attribution and build trust with any LLM.

The toolkit features explanation methods, quick start and elaborate example notebooks, tests, and documentation. The quick start notebooks can also be run in Google Colab.

Full Changelog: https://github.com/IBM/ICX360/commits/v0.1.0