Currently rule MD046 only checks for indented vs fenced but it seems that some dialects of markdown allow fencing to use ~~~ over ```.

It would be nice if a new rule was added (or MD046 expanded) where you could define whether fenced code blocks uses tildes, backticks or it should be consistent. Pretty much how lists work.

See https://sourceforge.net/p/tilde/wiki/markdown_syntax/ and https://www.markdownguide.org/extended-syntax/#fenced-code-blocks for two examples where ~ is allowed.