Refine roles for AMP Start & AMP by Example

Users have asked about the differences between AMP by Example and AMP Start, and how that changes how they use the two sites.

One key difference is that AMP Start comes along with a CSS framework that adds a lot of code upfront, but ultimately reduces the need for additional CSS for customization (because that can be done through applying classes). The tools we intend to build around AMP Start (configurator, theming) should make it even faster to customize, even for developers with little experience in CSS.

AMP by Example, on the other hand, tends to demo more functional, one-off examples which are likely easier to fold into an existing page structure. Customization is all by hand, so it's flexible, but not necessarily fast for developers with less CSS experience.

How can we help users quickly find what's right for them?
More research is needed :)

/cc @sebastianbenz @camelburrito