Add a demo for "Motion One"

[bryanbraun]

@mattgperry has built a new animation library called Motion One (https://motion.dev) that would be a great addition to this collection.

For an example of the changes that usually involved in adding a new demo, reference this PR for popmotion: #54

There are some helpful tips in the contribution guidelines.

[bryanbraun]

Fixed in #108. Thanks @anastasialanz!