feat: add quick-start demo

[Belyenochi]

Add Instructions to run kspan. [Issue link]: https://github.com/weaveworks-experiments/kspan/issues/4

[bboreham]

@Belyenochi do you think you will come back to this?

[fatsheep9146]

@bboreham If this pr is no longer active, I'd love to help. Could I create a new pr to give a doc for deploy a demo on kind?