Add compose sync example, maybe as default

[BretFisher]

Compose now has a alpha feature for syncing files and avoiding bind-mounts for local development. This is great for many reasons:

1. increased performance
2. reducing complexity for compose and dockerfile
3. removes need for moving node_modules and volume workarounds

First, we need an example (maybe lives in a compose-sync directory and then once feature is out of alpha/beta we make it the default example with a legacy directory for the old way with bind-mounts.