Summary:
* Include prerequisites.
* Add an example to Vizier section of running unit tests.
* Link to instructions for spinning up a Minikube cluster to deploy onto.
* Clarify the differences between Vizier and Pixie Cloud.
* Add workaround instructions for failed px deploy.
* Note when and where various commands in the instructions should be run and explain

Test Plan: N/A

Reviewers: michelle, vihang

Reviewed By: michelle
Signed-off-by: Hannah Stepanek <hstepanek@newrelic.com>

Differential Revision: https://phab.corp.pixielabs.ai/D9932

GitOrigin-RevId: 5e06b24b2f1af27871e728767762bdacf66e03d6