README: add "Checking if it is working" section

Related to #18.

README.md

@@ -55,6 +55,15 @@ Use `--access-log -` to output access logs to stdout.
 $ pipenv run hypercorn run:app
 ```
 
+*It is recommended to run litecord behind NGINX.* Because of that,
+there is a basic `nginx.conf` file at the root.
+
+### Checking if it is working
+
+You can check if your instance is running by checking the `/api/v6/gateway`
+path. And for basic websocket testing a tool such as [wss](https://github.com/hashrocket/ws)
+can be used.
+
 ## Updating
 
 ```sh

nginx.conf

@@ -1,6 +1,10 @@
-# Main litecord HTTP proxy.
+# litecord nginx file
+
+# this file is not considering any https happening,
+# those are manual and up to the instance owner.
+
 server {
-    server_name main.somewhere;
+    server_name example.tld;
 
     location / {
         proxy_pass http://localhost:5000;