feat!: remove ddIndent from state_block

[Mister-Hope]

For details see markdown-it/markdown-it#1139 and markdown-it/markdown-it#1140

[serkodev]

Thanks for the PR.

Although I agree that this prop is currently unused, at this stage I think we should keep it to maintain backward compatibility with the markdown-it plugin.

As you can see in the plugin, it checks if (state.ddIndent < 0) { return false }, and since undefined < 0 evaluates to false, removing the prop would change the existing behavior.

[Mister-Hope]

Yeah, indeed it will break the existing deflist plugin, however it would not break @mdit/plugin-dl: https://www.npmjs.com/package/@mdit/plugin-dl

The existing official plugin is not aligned to PanDoc deflist, see markdown-it/markdown-it-deflist#18 (which I haven't raised a pr yet because the latter one is not merged for months) and markdown-it/markdown-it-deflist#11

[serkodev]

Thanks for investigating this and for raising the issue. I also agree that it would be ideal to remove unused props. However, as I mentioned, for the sake of backward compatibility, we won’t be removing it at this stage.

Additionally, I believe the impact of having this extra prop for now is non-breaking. I hope you can understand. 🙏