docs: add new document for hello operator #783

Job	Run time
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 58s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	4m 16s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	4m 2s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	3m 46s
deployment (static, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	3m 43s
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 21s
deployment (static, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	4m 3s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 35s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	3m 33s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	3m 26s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	3m 26s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	2m 53s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-full.yaml)	3m 54s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-slim.yaml)	3m 3s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	3m 36s
	58m 43s

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