Add link to issue about documenting admin urls.

Web-Interface.md

@@ -4,3 +4,5 @@ SeaweedFS has web dashboards for its different services:
   For example: `http://localhost:9333`.
 * Volume server dashboards can be accessed on `http://hostname:port/ui/index.html`.
   For example: `http://localhost:8080/ui/index.html`
+
+Also see [#275](https://github.com/chrislusf/seaweedfs/issues/275).