I have tried to install new windows machine for buildkite and updated
some scrips and docs on along the way.
- Updated base image for k8s agent installation as it gave a warning that
previous version was old.
- Now buildkite secret is configured in a powershell script along with
tags (and possible other parameters).
- Split "windows_agent_start.ps1" to "..jenkins" and "..buildkite" as
some parameters are different.
- Created a "windows-development" machine in GCP stat can be resumed
to build docker images / expriment.
