Document Hystrix command configuration

[fitzoh]

The current HystrixGatewayFilterFactory documentation shows how to configure a fallback URL, but doesn't touch on any of the other hystrix configuration options which are available (setting a timeout is what I was personally looking for).

The documentation should be updated to note how the HystrixGatewayFilterFactory.Config.name maps to a HystrixCommandKey, and explain how that integrates with Hystrix configuration.

It would also be nice to include an example or two. I suspect that setting a timeout will be the most commonly used configuration option, and is the only one I could find an example of in the tests.

spring-cloud-gateway/spring-cloud-gateway-core/src/test/resources/application.yml

Line 256 in 61badf8

hystrix.command.successcmd.execution.isolation.thread.timeoutInMilliseconds: 5000

Getting a bit off topic, but if that suspicion is correct, it might make sense to add some sugar around timeouts and make that a first class part of the DSL.