GlobalFilter documentation should be update WRT Order

[dancerjohn]

Describe the bug
The documentation WRT GlobalFilter and ordering suggests that GlobalFilter and GatewayFilter order can be controls via the Ordered interface (or @ordered annotation). However, it appears that regardless of the GlobalFilter order, the GatewayFilters are applied first. This should be clarified in the documentation or (preferably) fixed so that a GlobalFilter with a higher precedence than a GatewayFilter will be applied first.

From: https://docs.spring.io/spring-cloud-gateway/reference/spring-cloud-gateway/global-filters.html
"When a request matches a route, the filtering web handler adds all instances of GlobalFilter and all route-specific instances of GatewayFilter to a filter chain. This combined filter chain is sorted by the org.springframework.core.Ordered interface, which you can set by implementing the getOrder() method."

This comment is what clued me in:
#2784 (comment)

[spencergibb]

I wonder if #2934 and #2912 fixed this?

[dancerjohn]

This is what I BELIEVE is the distinction. In each set (global vs non-global) order is respected. However relative the other opposite set, non-global are applied before global regardless of relative order. Also 2934 is in reference to the Order annotation vs Ordered interface. I believe I tried both. That said, I am using 3.1.9 so possible 2934 might address it.