Change websocket host to localhost in readme

Author: qdm12

README.md

@@ -91,11 +91,13 @@ This is one of three components required for Project Lightspeed. Project Lightsp
     ```sh
     docker run -it --rm \
       -p 8000:80/tcp \
-      -e WEBSOCKET_HOST=lightspeed-websocket-hostname \
+      -e WEBSOCKET_HOST=localhost \
       -e WEBSOCKET_PORT=8080 \
       grvydev/lightspeed-react
     ```
 
+    Where your websocket host from the browser/client perspective is accessible on `localhost:8080`.
+
 1. You can now access it at [localhost:8000](http://localhost:8000).
 
 ### Locally