TestKube integration write-up (Part 2)

[gadkins]

This task is for @gopuman and is a continuation of UffizziCloud/harbor-test#15

Part 2: Write-up

Polish the repo: Add a summary in the Readme describing the purpose of the repo; Make sure the code/examples are polished
Describe what you did and why
Preface describing ephemeral environments / pull request environments (see existing write-ups here and here with CI examples here and here)
What is TestKube? + Benefits of automated testing w/ TestKube
Describe the integration process