docs: add new document for hello operator #774

Job	Run time
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 50s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	3m 53s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	3m 48s
deployment (static, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	4m 23s
deployment (static, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	3m 50s
deployment (static, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-full.yaml)	4m 26s
deployment (static, EMQX, emqx, config/samples/emqx/v2beta1/emqx-slim.yaml)	4m 2s
deployment (static, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	4m 13s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-slim.yaml)	3m 44s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta3/emqxenterprise-full.yaml)	3m 21s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-slim.yaml)	3m 21s
deployment (helm, EmqxEnterprise, emqx-ee, config/samples/emqx/v1beta4/emqxenterprise-full.yaml)	3m 24s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-slim.yaml)	3m 27s
deployment (helm, EMQX, emqx, config/samples/emqx/v2alpha1/emqx-full.yaml)	3m 51s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-slim.yaml)	2m 57s
deployment (helm, EMQX, emqx, config/samples/emqx/v2beta1/emqx-full.yaml)	3m 42s
	1h 0m 12s

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