Consider updating the quickstart

[maia-iyer]

Currently our quickstart focuses on deploying Tornjak + SPIRE on minikube.

However, given the new efforts in the helm charts, deployment is easier. We could possibly create a shorter quickstart that makes it easier to get started with tornjak.

Preferably, we focus less on the deployment and more on Tornjak functionality:

• The API structure
• The UI structure