Factor out whole-file reading into a utility function
Convert MarkdownWriter to a torch.class
Update tests for parsing with whitespace

Add tests for extraction part of the code

Move common functionality to a testUtils file
Change pl classes to torch classes
Fix class detection with no parent class
Extract classes as well as functions
Parser now creates entities for whitespace
Black box test for dokx-extract-markdown
Improve MarkdownWriter

Small refactoring, and adjust output to be closer to torch core docs