Improve component modularity

[stephenmparke]

Thoughts:

• Have components include default wrappers (ex: each top-level card automatically has article.card and its 3 child components (header, body, footer) ). Needs the ability to exclude the footer, for example.
• Have ability to pass through custom card heading text via props. Could also be used to pass in feed info for down the road.
• Add a logical way to define or swap component type (ex: "tile" components that already have the dark gradient over background images, or additional visual presets in the future)

[stephenmparke]

I'm going to go ahead and close this. Most of this got accomplished or decided to not do.