add documentation for minikube deployment using skaffold.

[beerfranz]

Linked to the PR for adding Skaffold configuration: https://github.com/api-platform/api-platform/pull/2457 If the PR on api-platform/api-platform is refused, and this PR for the documentation is accepted, need to change the doc before merging (replace links to /api-platform/helm/skaffold*.yaml by the content of this files.)

[GregoireHebert]

Could be nice to merge this since the project does now benefit from the skaffold configuration :)

[dunglas]

Thanks!