docs: update env setup

Author: tituschewxj

apps/matching-service/README.md

@@ -22,7 +22,13 @@ cd ./apps/matching-service
 go mod tidy
 ```
 
-3. Start the WebSocket server:
+3. Create a copy of the `.env.example` file as an `.env` file with the following environment variables:
+
+- `PORT`: Specifies the port for the WebSocket server. Default is `8081`.
+- `JWT_SECRET`: The secret key used to verify JWT tokens.
+- `MATCH_TIMEOUT`: The time in seconds to wait for a match before timing out.
+
+4. Start the WebSocket server:
 
 ```bash
 go run main.go
@@ -88,12 +94,6 @@ If no match is found after a set period of time, the server will send a timeout
 
 If the server encounters an issue during the WebSocket connection or processing, the connection will be closed without any error message. The client should treat the unexpected closing as an error.
 
-### Environment Variables
-
-- `PORT`: Specifies the port for the WebSocket server. Default is `8081`.
-- `JWT_SECRET`: The secret key used to verify JWT tokens.
-- `MATCH_TIMEOUT`: The time in seconds to wait for a match before timing out.
-
 ## Testing
 
 Utilize `./tests/websocket-test.html` for a basic debugging interface of the matching service. This HTML file provides an interactive way to test the WebSocket connection, send matching requests, and observe responses from the server.