Add a Katacoda scenario that can act as a playground for users
to experiment with Tekton in a sandbox environment.

This environment provides a 2-node Kubernetes cluster with the
following projects installed:
- Pipelines v0.14.3
- Dashboard v0.8.2
- CLI v0.11.0

Typical startup time is <1minute, but may take 2 or 3 minutes
in some cases. The installation should not require any manual
steps by the user.