Prepare v0.9.0 release

CITATION.cff

codemeta.json

docs/index.yaml

helm/Chart.yaml

helm/values.yaml

...tions/uc1-beam-flink/resources/jobmanager-deployment.yaml

...ions/uc1-beam-flink/resources/taskmanager-deployment.yaml

...s/uc1-beam-samza/resources/uc1-beam-samza-deployment.yaml

...efinitions/uc1-flink/resources/jobmanager-deployment.yaml

...finitions/uc1-flink/resources/taskmanager-deployment.yaml

...1-hazelcastjet/resources/uc1-hazelcastjet-deployment.yaml

...tions/uc1-kstreams/resources/uc1-kstreams-deployment.yaml

...ad-generator/resources/uc1-load-generator-deployment.yaml

...tions/uc2-beam-flink/resources/jobmanager-deployment.yaml

...ions/uc2-beam-flink/resources/taskmanager-deployment.yaml

...s/uc2-beam-samza/resources/uc2-beam-samza-deployment.yaml

...efinitions/uc2-flink/resources/jobmanager-deployment.yaml

...finitions/uc2-flink/resources/taskmanager-deployment.yaml

...2-hazelcastjet/resources/uc2-hazelcastjet-deployment.yaml

...tions/uc2-kstreams/resources/uc2-kstreams-deployment.yaml