docs: explain quantity data type for analysis targets #12545

Job	Run time
Prepare CI Run	4s
Store tag of the built images	4s
Unit Tests (lifecycle-operator, lifecycle-operator/)	44s
Unit Tests (metrics-operator, metrics-operator/)	46s
Build Docker Image (lifecycle-operator, lifecycle-operator/)	1m 30s
Unit Tests (scheduler, scheduler/)	28s
Build Docker Image (metrics-operator, metrics-operator/)	2m 6s
Build Docker Image (scheduler, scheduler/)	1m 43s
Unit Tests (certificate-operator, keptn-cert-manager/)	1m 14s
Build Docker Image (deno-runtime, runtimes/deno-runtime/)	32s
Build Docker Image (python-runtime, runtimes/python-runtime/)	32s
Build Docker Image (certificate-operator, keptn-cert-manager/)	1m 32s
Component Tests / Component Tests	2m 4s
Publish helm chart changes to charts repo	0s
End to End Tests / Run E2E Tests (lifecycle-operator, lifecycle-operator/)	1m 43s
Load Tests / Run load Tests	6m 27s
End to End Tests / Run E2E Tests (scheduler, scheduler/)	3m 2s
Performance Tests / Performance Tests	1m 50s
Integration Tests (gates_off, allowed_ns_off) / Run Integration Tests	9m 36s
Integration Tests (gates_off, allowed_ns_on) / Run Integration Tests	3m 17s
Integration Tests (gates_on, allowed_ns_off) / Run Integration Tests	9m 32s
Integration Tests (gates_on, allowed_ns_on) / Run Integration Tests	2m 56s
	51m 42s

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