Feature/sphinx tutorials

[jcharkow]

Add Sphinx tutorials and also add init for API documentation building. Good setup for doing relative imports

[jcharkow]

I don't know if this is worth rush merging for better import setup or to wait and do it later because seems to be a bunch of conflicts

[jcharkow]

@singjc I think this is ready for review when you have a chance. My main concern is to ensure that I did not break anything with the actual codebase. I had to remove some documentation in the codebase to get automatic sphinx documentation to work. I also added GenericChromatogramLoader and GenericSpectrumLoader because they are easier to describe in the docs.