I've been using Markdown for a while and know what you mean. I just came across this article last week: https://opensource.com/article/22/8/drop-markdown-asciidoc. Maybe it could help you.
The idea of Markdown isn't bad - separate the writing from the design. It's just horribly designed. I'd actually love to see a basic rich text document format based on a very strict subset of HTML with no JS, extremely limited CSS and basic tags - created for reading and writing, unlike most web pages - but still compatible with the full spec. Like an editable ePub or mobi format.
For anyone who happens upon this later, after finishing the resume, I was unpleasantly surprised to find out the CSS printing rules for page breaks don't work with CSS grid, making printing a PDF a nightmare.