New Demo: Microsoft Adaptive Cards

[kumilingus]

How to embed existing HTML rendered by a third-party library into a shape in JointJS? For instance, using Microsoft's Adaptive Cards as presented in this CodePen.

The example implements a custom view responsible for rendering interactive HTML cards inside foreign objects and synchronizing the size of the view and the model, since the size of the HTML may change over the lifetime of the card.

It also demonstrates the use of the markdown language inside the shapes using the markdown-it library.