#Feat: Add option to specify smartypants substitutions

[Buzut]

Not all languages use the same punctuation signs. For instance, in French double quotes are usually chevrons « & », it's different in German etc.

For that reason, it would be super handy to be able to specify chars substitution for smartypants.

[curbengh]

Too bad marked (used by this plugin) doesn't have a built-in mechanism to specify quotes. The only way I can think of is through its extensibility.
Meanwhile, markdown-it (utilized by hexo-renderer-markdown-it) can easily configure it. The hexo plugin can parse the option.

[Buzut]

Thank you for getting back to me.
Yes, so sad the plugin won't be able to do it. I don't really want to migrate to another renderer at this point though.
I'll take a look at its extensibility system.

[curbengh]

PR welcome of course.

[tomap]

I'm not sure migrating to https://github.com/hexojs/hexo-renderer-markdown-it is very complex :)