Add settings for enforced styles to presets

[jablko]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)
• If applicable, I’ve added docs and tests

Description of changes

What I did was, for each preset rule with remark-stringify options in that rule's "fix" documentation, I added that option to the preset's settings.

What this does is, you can apply the preset's remark-stringify options with, e.g.

remark --output --use remark-preset-lint-markdown-style-guide input.md

For example:

• remark-preset-lint-markdown-style-guide uses [remarkLintUnorderedListMarkerStyle, '-']
• remark-lint-unordered-list-marker-style's "fix" documentation points to settings.bullet
• ∴ I added bullet: '-' -> remark-preset-lint-markdown-style-guide's settings

[wooorm]

Probably a good idea!
This should be included in the docs at least.
It’s a breaking change. I’m open to working towards new majors (I’d also want to improve some error messages, which could be considered a major change as well), though that should probably come after by the work on improving markdown formatting which I mentioned in #281 (comment)

[wooorm]

Do you have ideas on how to test and document these additions?
What are your thoughts on the order in which your PRs should land?
And, how about the breaking changes? I guess that if we’re doing this one, we can break other things too?

[jablko]

• I've added Settings sections to each of the presets' readmes.

Thanks for merging #284 (comment)! Ideally I'd like to land #286 and this one (#282 (comment)), then rebase #279 (review)?