make carto.js templates more carto-like

[andy-esch]

E.g., the selectors on this should be more in line with the brand: https://carto.com/academy/t/03-cartodbjs-ground-up/lesson-4/bonus-header-map.html (code here)

There are more here: https://github.com/CartoDB/academy/tree/master/_app/t/03-cartodbjs-ground-up

[andy-esch]

@carlostallon, could we get some help from the design team on this?

[carlostallon]

How could we help you here, making a design proposal or also code it?

[andy-esch]

I'd be happy to take a swing at making it look more carto-like, but would need to learn about the css classes that you all use.