Create Jetpack Compose Example

[gracefh]

Create a Jetpack Compose Example, which displays as follows in storybook:

Also added a gradient component in order to make this component, which just specifies a linear gradient (see the rectangles in the image above)

[joshpoll]

Nit: Could you please add an attribution for this example? I think the link we use in the paper is good enough. You can just leave it as a comment in the story. Thanks!