Add Buildkite status badge to the KernelAbstractions.jl README?

Created by: DilumAluthge

As far as I can tell, Buildkite provides README status badges (similar to the status badges provided by Travis, AppVeyor, GitHub Actions, etc.): https://buildkite.com/docs/integrations/build-status-badges

It would be great to add the Buildkite status badge to the KernelAbstractions.jl README.