Cross-project coordination

I maintain the Print project which prints rendered Markdown with support for a variety of extensions eg Mermaid and Katex.

I gave up on the Microsoft internal rendering pipeline because they keep making breaking changes. Consequently I am supporting extensions directly. I think we should coordinate so that your editor and Print use the same conventions for extension, for a good end to end experience.

One small example is for tables. I have two extensions in mind, one of which is best implemented in an editor like yours.

1. We can extend the right-alignment notation `|---:|` to also permit the characters [0-9$] where a digit means right-align and round to that many decimal places, and $ means right-align, 2 dec places with a currency symbol.
2. If the usee employs Excel syntax I can use the hyperformula library to evaluate formulae for print/preview.