Update .env.sample

Author: jq1836

.env.sample

@@ -4,7 +4,7 @@ COMPOSE_PATH_SEPARATOR=:
 COMPOSE_FILE=docker-compose.yml:docker-compose.dev.yml
 
 ## Frontend variables
-FRONTEND_PORT=3000
+FRONTEND_PORT=
 # BASE_URI only needs to be provided if hosting outside of cluster
 BASE_URI=
 
@@ -18,3 +18,10 @@ USER_SVC_DB_URI=
 JWT_SECRET=
 EMAIL_ADDRESS=
 EMAIL_PASSWORD=
+
+## Matching service variables
+MATCHING_SVC_PORT=
+MATCHING_SVC_REDIS_PORT=
+
+## API Gateway variables
+API_GATEWAY_PORT=