Foreign quotes support?

[virtualritz]

It would be nice if Options::ENABLE_SMART_PUNCTUATION: turned ' and " into localized quotes.

An additional way to switch this on (Options::ENABLE_LOCALISED_QUOTES?) and select a supported language would be needed too, I guess.

No need to add detection of primary/secondary. The Markdown author itself should have control over this implcitly by using single/double quotes.

[Martin1887]

This is a relatively big feature, and I think it is out of the scope of the basic pulldown-cmark renderer.

Note the aim of this crate is basically parse Markdown, and the renderer is only a basic utility showing what can be do. An external renderer using pulldown-cmark is welcome, and this feature would be useful there, check #645.