Merge pull request #10225 from k8s-infra-cherrypick-robot/cherry-pick-10146-to-release-1.8

[release-1.8] Clarify TCP/UDP service docs

Author: strongjz

docs/user-guide/exposing-tcp-udp-services.md

@@ -1,6 +1,8 @@
 # Exposing TCP and UDP services
 
-Ingress does not support TCP or UDP services. For this reason this Ingress controller uses the flags `--tcp-services-configmap` and `--udp-services-configmap` to point to an existing config map where the key is the external port to use and the value indicates the service to expose using the format:
+While the Kubernetes Ingress resource only officially supports routing external HTTP(s) traffic to services, ingress-nginx can be configured to receive external TCP/UDP traffic from non-HTTP protocols and route them to internal services using TCP/UDP port mappings that are specified within a ConfigMap.
+
+To support this, the `--tcp-services-configmap` and `--udp-services-configmap` flags can be used to point to an existing config map where the key is the external port to use and the value indicates the service to expose using the format:
 `<namespace/service name>:<service port>:[PROXY]:[PROXY]`
 
 It is also possible to use a number or the name of the port. The two last fields are optional.