fix: typo in localhost in README

See merge request !4

Increase application logging

See merge request !3

Following review, adds:
- Stop message on lifespan end
- Improve logic for flattening list of bools
- Logs host IP address
- Logs errors if unusual responses from k8s API

Also increases comments, and improves tests

Adds logging to the container to capture:
- Application startup, with settings logged
- When no containers are found
- The initial container status
- Whenever any container status changes
- Whenever the overall status is a failure

Anytime these logs are made, and the information is available, the full
list of containers with their respective statuses are logged.

Initialise GKE load balancer healthchecker

See merge request !1

Improves the pod readiness endpoint, unit tests, and a local
minikube-focussed integration test setup.