Jeff Atwood tried to fix this, but the creator of Markdown does not seem keen to cooperate with any attempts to standardize it.[1]
Since he owns the trademark, standardization will likely be impossible without his cooperation. Not to come down on John Gruber, I understand his position and he’s a cool cat... it’s just an unfortunate shortcoming of markdown, which I otherwise love.
With the exception of ordered lists. I can never figure out how to get multiple paragraphs or interstitial content into ordered lists, and it always resets the counter to 1... but everything else is great!
[1] https://blog.codinghorror.com/standard-markdown-is-now-commo...
https://github.com/asciidoctor/asciidoctor.org/blob/master/d...
Here is a very short intro on rendering in your browser: https://www.youtube.com/watch?v=4LOB3WeOUJk
Asciidoc.org at some time in the future should be the page for the language spec. The biggest feature is probably that you can produce DocBook and it's very easy!