Separate card data from view

[yoshiask]

Everything about cards on the website (such as the Launch 2020 and Discord blocks on the Home page) is hard-coded in their respective TSX file. It would be much more convenient for the content of those cards to be stored separately from the view itself in a JSON file.

This makes it easier for other services and apps to consume that data. The UWP Community client would make use of this, rather than attempting to parse the TSX from GitHub or scrape the webpage. This could also allow specific cards to be embedded into other websites (like a Windows Central article, for example).