Feature request: Equation handling.

[ilzolende]

Many documents use inline equations extensively. Given this, paragraph-form alerts replacing equations can disrupt the editing workflow. As it stands, I've replaced the equation alerts with \\(>>>>> gd2md-html alert: equation\\)) for easier conversion to MathJax, but there's probably some better option.

In particular, when I've downloaded a Google Doc as a Word document and converted it to Markdown using Pandoc, the user experience was overall worse (hence why I like this extension), but it was able to gracefully convert equations into LaTeX. I'm sure some users would appreciate a conversion to inline MathJax as an option. It'd certainly be amazing for me.

Thanks for developing this tool, it's very nice to have.