Update markdownlint configuration for list indentation

[froschdesign]

The configuration for markdownlint has been updated to include setting the indentation of list item to 4 spaces ("MD007"). This is intended to ensure the correct formatting for markdown documents in MkDocs.

References:

• https://github.com/DavidAnson/markdownlint/blob/main/doc/md007.md
• https://python-markdown.github.io/#differences

[Ocramius]

Ah, just a note: this obviously broke a hell of pipelines downstream.

@froschdesign is 2 or 4 spaces acceptable, or is 4 strictly necessary for our needs?

[Xerkus]

It is expected.

Strictly 4 due to mkdocs using original markdown, not commonmark, with some strict interpretations of said spec.

See: https://github.com/mezzio/mezzio/pull/179