Added the example application referenced in the guide for transactional
processing with Streams.

Everything is working quite nicely!

closes #94

Removed a currently unused Stream CRD `ttl` field. This will be
reintroduced at a future point.

Removed old RFCs pattern, as these are all recorded in issues now.

Added artifacthub-repo.yml for ArtifactHub ownership.

Each Token will now have its own HMAC key created for using in the
initial creation of the Token's JWT as well as for all subsequent
verification as the JWT is used.

Downstream systems, such as Streams, simply observe the Secrets and load
their decoding keys for quick and easy verification when establishing
authN & authZ for a new connection to the system.

closes #60