Should sync rendering setting with markdown.math.enabled?

[yhatt]

VS Code 1.58 will add a built-in math typesetting support for Markdown Preview with KaTeX. User can preview math typesetting in Markdown without any extensions.

Luckily this rendering would not conflict with Marp's math support, and there is high compatibllity with Marp syntax.

Math rendering can disable through markdown.math.enabled setting. Marp for VS Code is extending built-in preview, so following this setting even in Marp preview may be reasonable when keep to mental model of Markdown preview, just like #226.

On the other hand, Marp supports KaTeX and MathJax as typesetting library and user can choose one of which. The difference of functionality for math rendering between VS Code preview and Marp may become large with advances. Thus, keeping split setting like the relation between markdown.preview.breaks and markdown.marp.breaks may be better too. (In this case, we would add markdown.marp.mathTypesetting: "off" option to disable math, for following the use case of markdown.math.enabled)

[yhatt]

We are going to take the latter in #258.