update readme

Author: kstep

README.md

@@ -9,5 +9,6 @@ builds on this feature to provide modern AJAX autoindex facility.
 Minimal nginx config example is in `nginx.conf` file included in the repository.
 Once nginx is configured and running, put contents of the repository under some
 document root, so nginx can serve it, and open `index.html` in browser via nginx.
-You may need to update `.constant("FILES_BASE_URL", "")` configuration option
-to point to the base URL configured with `autoindex_format json;` in nginx.
+
+To configure, rename `config-example.json` to `config.json` and set `base_index_url`
+option to a path configured in nginx with `autoindex_format json;`.