Suggestion: Markmap formatting

[ramenatorr]

I typically start note files from scratch and don't save them until later on. So, for my particular usage, it'd be nice if Markmap didn't need a saved .mm.md file to exist before interpreting it as a Markmap.

I'm not entirely sure of the viability of this, but what could be useful is being able to set the language to markmap in the bottom-right corner as an example. This is similar to setting the language to something like Markdown or JSON. This language interpretation could then trigger the Markmap VS Code extension to run and bring up the preview pane, etc.

Setting langauge:

[gera2ld]

Sounds like a duplicate of #6