Some markdown elements produce invalid html

[yngwi]

For instance: https://data.nampi.icar-us.eu/info/model

• <figure> cannot appear as a descendant of <p>.
• React does not recognize the isHeaderprop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercaseisheader instead. If you accidentally passed it from a parent component, remove it from the DOM element. th