Update README.md

Update package structure for PyPI: fix setup.py, update README with installation steps, add install script

Merge branch 'main' of https://huggingface.co/chest2vec/chest2vec_0.6b_cxr

Add pip install support: setup.py, package structure, and updated README with pip install chest2vec

Update chest2vec.py

Resolve conflicts after stash pop

initial commit