Guide Configuring Messaging Application contains section 5.5. Handling Slow Consumers. This section contains information about purpose of this feature. However, there is no example how can this feature be configured.
Configuration of slow consumer handling is done for address by setting attributes slow-consumer-check-period, slow-consumer-policy, slow-consumer-threshold in address-setting. How to configure address-setting is described in chapter 3.4. Address Settings . This section also contains table Configuration Attributes for address-settting with brief description of attributes.
Section _ 5.5. Handling Slow Consumers_ should mention that configuration is done by setting attributes of address-setting and contain at least link to slow-consumer-* attributes in table in chapter 3.4. Address Settings, or detail explanation of mentioned attributes. Example of configuration should be provided as well.
Basically it looks like following one :

<address-setting name="#" slow-consumer-threshold="10" slow-consumer-policy="KILL" slow-consumer-check-period="100" .... />

Example above is applied to all destinations, single consumer is considered as slow when receives max 10 messages per second, slow consumers are killed, check for slow consumers if done every 100 seconds.

Content contained in Artemis documentation in section Configuration required for detecting slow consumers should be also mentioned in documentation.