Fix link to configmap.md in documentation (#433)

Author: Dean-Coakley

docs/nginx-ingress-controllers.md

@@ -19,7 +19,7 @@ The table below summarizes the key difference between nginxinc/kubernetes-ingres
 | **Load balancing configuration** |
 | Merging Ingress rules with the same host | Supported | Supported | Supported |
 | HTTP load balancing extensions - Annotations | See the [supported annotations](https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/nginx-configuration/annotations.md) | See the [supported annotations](configmap-and-annotations.md) | See the [supported annotations](configmap-and-annotations.md)|
-| HTTP load balancing extensions -- ConfigMap | See the [supported ConfigMap keys](https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/configmap.md) | See the [supported ConfigMap keys](configmap-and-annotations.md) | See the [supported ConfigMap keys](configmap-and-annotations.md) |
+| HTTP load balancing extensions -- ConfigMap | See the [supported ConfigMap keys](https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/nginx-configuration/configmap.md) | See the [supported ConfigMap keys](configmap-and-annotations.md) | See the [supported ConfigMap keys](configmap-and-annotations.md) |
 | TCP/UDP | Supported via a ConfigMap | Supported via a ConfigMap with native NGINX configuration | Supported via a ConfigMap with native NGINX configuration |
 | Websocket  | Supported | Supported via an [annotation](https://github.com/nginxinc/kubernetes-ingress/tree/master/examples/websocket) | Supported via an [annotation](https://github.com/nginxinc/kubernetes-ingress/tree/master/examples/websocket) |
 | TCP SSL Passthrough | Supported via a ConfigMap | Not supported | Not supported |