[Feature Request] Create an org-md-toplevel-hlevel variable to allow users to set the level of top level headings in markdown export

["Rohit Patnaik" <quanticle@quanticle.net>]

Hello,

I've been exporting several of my org-mode notes to markdown recently, and I've been running into an issue where I've had to manually adjust the level of the top level headings in my exported notes because the wiki system I'm importing the notes to reserves h1 (i.e. #) for page titles, using h2s (i.e. ##) for sections within the page itself.

I noticed that ox-html.el has a org-html-toplevel-hlevel variable, which allows the user to set the heading level of top-level headings within the exported content. Would there be any problems with implementing a similar variable (e.g. org-md-toplevel-hlevel) to allow the user to set the heading level of top level headings within exported markdown content?

It looks like it would be a small change, and I'd be happy to implement it myself, but I thought I'd run it by the list to see if there were any major issues that might arise from making this change.

Thanks,
Rohit Patnaik