Pandoc-crossref and block math

[borir]

Pandoc-crossref (https://hackage.haskell.org/package/pandoc-crossref-0.1.0.0) is a very useful tool for equation numbering and cross references as markdown dialects usually don't support them natively. However, markdown-it-katex does not work properly with the syntax of pandoc-crossref. It seems that markdown-it-katex requires the ending $$ delimiter to be at the tail of the last line, but the label tags of pandoc-crossref, like {#eq:my-label}, must be put after the ending $$ delimiter. Would you care of this?