Merge pull request #4153 from Niksko/use-regex-annotation

Add clarification on how to enable path matching

docs/user-guide/ingress-path-matching.md

@@ -6,6 +6,7 @@
     Regular expressions and wild cards are not supported in the `spec.rules.host` field. Full hostnames must be used. 
 
 The ingress controller supports **case insensitive** regular expressions in the `spec.rules.http.paths.path` field.
+This can be enabled by setting the `nginx.ingress.kubernetes.io/use-regex` annotation to `true` (the default is false).
 
 See the [description](./nginx-configuration/annotations.md#use-regex) of the `use-regex` annotation for more details.