BREAKING CHANGE
- Previously it ignored the topmost directory, ie. a file
of name `a.b.c.rst` would have the name `b/c.rst`. Now for `a.b.c.rst`,
`a/b/c.rst` is generated.
Feat
- **core**: process additional arguments and raise error if command fails
- **__main__**: add additional flags to parser
- **core**: handle namespace and packages properly
Refactor
- **init**: change the logger format to include `filename:lineno`
- **__init__**: use `%` formatting and add `__future__` import
- move codebase into `src` directory