Google style support

[staticf0x]

This PR adds basic support for google style docstrings.

Resources used:

• https://google.github.io/styleguide/pyguide.html#s3.8-comments-and-docstrings
• https://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html

Supported features

• Function description, short and long
• Arguments parsed into a list
• Return values, raised exceptions, yields for generators
• Example, note, todo blocks
• Multiline argument descriptions
• Indented argument descriptions
• Inline markdown
• Underscore escaping (__init__.py, __str__, ...)
• RST-like links
  • The official Google guide doesn't mention these, but this guide does
• Literal blocks
  • Same as with RST-like links

Example

Screenshot from Sublime Text 4 before this change:

and after with the support enabled:

This is the code used for this example:

def something(a: str) -> str:
    """Do **something**. But not __init__.py.

    Some longer description here, that's allowed.
    See ``Args`` in `self`.

    Args:
        a (str): some arg with type
                 with multiline
                 comment
        b:
            some arg without type
        *args: Yayaya
        **kwargs: dadada

    Returns:
        str: the same *stuff*

    Raises:
        ValueError: if something bad happens
                    but y'know
        KeyError: if something else equally bad happens

    Examples:
        Use it like this.

    Note:
        Do not use this function. Or https://github.com.

    Todo:
        * Not sure
        * Test
    """
    return a

[krassowski]

Thank you @staticf0x