Add documentation for environment variables

Environment variables

Production:

Variables name	Default value	Usage
NAMESPACE	default	Determines the namesspace of the KubernetesClient. Used in the KubernetesBenchmark
THEODOLITE_EXECUTION	./config/BenchmarkExecution.yaml	The complete path to the benchmarkExecution file. Used in the TheodoliteYamlExecutor.
THEODOLITE_BENCHMARK_TYPE	./config/BenchmarkType.yaml	The complete path to the benchmarkType file. Used in the TheodoliteYamlExecutor.
THEODOLITE_APP_RESOURCES	./config	The path under which the yamls for the ressources for the subexperiments are found. Used in the KubernetesBenchmark
``

Development:

Variables name	Default value	Usage
NAMESPACE	default	Determines the namesspace of the KubernetesClient. Used in the KubernetesBenchmark
THEODOLITE_EXECUTION	./../../../../config/BenchmarkExecution.yaml	The complete path to the benchmarkExecution file. Used in the TheodoliteYamlExecutor.
THEODOLITE_BENCHMARK_TYPE	./../../../../config/BenchmarkType.yaml	The complete path to the benchmarkType file. Used in the TheodoliteYamlExecutor.
THEODOLITE_APP_RESOURCES	./../../../../config/	The path under which the yamls for the ressources for the subexperiments are found. Used in the KubernetesBenchmark

For Development gradle.run configuration:

NAMESPACE=default;THEODOLITE_BENCHMARK=./../../../../config/example-benchmark-yaml-resource.yaml;THEODOLITE_APP_RESOURCES=./../../../../config;THEODOLITE_EXECUTION=./../../../../config/example-execution-yaml-resource.yaml;MODE=operator

Alternative:

export NAMESPACE=default
export THEODOLITE_BENCHMARK=./../../../../config/example-benchmark-yaml-resource.yaml
export THEODOLITE_APP_RESOURCES=./../../../../config
export THEODOLITE_EXECUTION=./../../../../config/example-execution-yaml-resource.yaml
export MODE=operator
./gradlew quarkusDev