suggestion: figure with caption

[petermolnar]

Hi Emanuil,

I was recently inserting a CC image to one of my posts using Parsedown Extra to be displayed and I realized I cannot use it for HTML5 figure to add caption properly.

I came across Markdown Extra Extended and it's figure solution and I was wondering how to add this to Parsedown.

To be honest the code structure of Parsedown is extremely unfamiliar for me, and I will try to add this myself, but I have a feeling it would take much less time for you.