Adjust Benchmark Definitions for Operator

Depends on !131 (merged), !139 (merged), !153 (merged)

This is just an early draft, for a final version, we need to address the following items:

• Replace installation via install-configmaps.sh script by according additions to the Helm chart
• Reduce the amount of configMaps --> abandoned (see #240 (closed))
• Allow for additional benchmark definitions

docs/creating-a-benchmark.md

+* Create a benchmark for operator mode
+* Create a benchmark for standalone mode
+* Deploy a benchmark
+
+## Creating a benchmark for operator mode
+
+
+## Creating a benchmark for standalone mode
+
+Creating a benchmark in standalone mode is similar to operator mode. However,
+instead of defining a benchmark as `Benchmark` resource, it is defined as a
+benchmark YAML file. Such a file deviates in the following points from a
+`Benchmark` resource:
+
+* The fields `apiVersion`, `kind` and `metadata` should be removed.
+* The benchmark's name (`metadata.name` in `Benchmark` resources) must be defined by the top-level field `name`.
+* Everything that is defined in `spec` has to be moved to the top-level.
+
+**TODO: example**
+
+**TODO: Create a ConfigMap containing the benchmark YAML files as well as all Kubernetes resources for that benchmark + deploy**
\ No newline at end of file