[FR] Support markdown and JSX in card objects

[techy-robot]

I know the Card's view has not formerly been finished, but I want to use it anyway. Currently, it on supports Literals in contents, which shows plain text and nothing pretty, even markdown links. I look at the history, and when it was initially implemented it was a wrapper for normal jsx objects. I am curious about the reasoning why the change, and it would be nice to at least have links render properly.