Markdown with HTML issues

[m-mohr]

Here's an example of a Markdown file with HTML tags (img/figure), which doesn't render:

https://raw.githubusercontent.com/Open-EO/openeo.org/master/documentation/1.0/datacubes.md

[severo]

To reproduce: https://viewers.source.coop/?url=https%3A%2F%2Fraw.githubusercontent.com%2FOpen-EO%2Fopeneo.org%2Fmaster%2Fdocumentation%2F1.0%2Fdatacubes.md&viewer=markdown

10:1-10:10: Unexpected closing tag `</figure>`, expected corresponding closing tag for `<img>` (8:5-8:306)

[severo]

Compare with https://github.com/Open-EO/openeo.org/blob/master/documentation/1.0/datacubes.md