Black plugin for the Python Language Server.

- Can either format an entire file or just the selected text
- The code will only be formatted if it is syntactically valid
  Python
- Text selections are treated as if they were a separate
  Python file. This also means that an indented block of code
  cannot be formatted
- Will use your project's pyproject.toml if it has one.

Using pyls-black while yapf and autopep8 are installed, may
lead to unexpected results!