Scriptconfig

Added

* `Config.to_dict` to have a method consistent with pandas API

Changed

* Loading from a config yaml file will ignore the special `__heredoc__` key.
This lets the user add multi-line documentation to their config files.

Fixed
* Tests on windows

Changed
* Obtained public release approval, first public release.

Removed
* Removed exposed internal functions from the top level API

Changed
* Reworked load
* Separate out requirements

Added
* Add docs

Fixed
* fixed `cmdline` bugs

Changed
* Rework imports

Added
* Add `Config.argparse` and use it internally in load
* Initial implementation