Add more and better pictures to README

[Cliabhach]

Show off different generators and interesting combinations of CutoutViewLayoutParams.

[Cliabhach]

We'll need a few new layouts if we're going to cover all the possible configurations. I'm thinking

1. CVI overlaying a ViewPager
2. full screen vertical-scrolling content with side-aligned CVI
3. inline child view population, with a dummy/non-interventionist Generator

And perhaps a different fragment for each one.