docs: add new document for hello operator #772

Job	Run time
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 48s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	3m 58s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	4m 11s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	3m 48s
deployment (static, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	3m 25s
deployment (static, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-full.yaml)	4m 8s
deployment (static, EMQX, emqx, config/samples/emqx/v2beta1/emqx-slim.yaml)	3m 43s
deployment (static, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	4m 9s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 41s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	3m 29s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	3m 35s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	3m 32s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	3m 9s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-full.yaml)	4m 15s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-slim.yaml)	3m 17s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	3m 26s
	59m 34s

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