added template instructions in README

README.md

@@ -2,6 +2,7 @@
 ==========
 # Run the server-side FastAPI app
 ## In development mode
+Using the template files, you first need to create backend/.env and backend/cameras.py.
 You can start a virtual environment with the following instructions.
 
 ```sh
@@ -34,6 +35,8 @@ Run the server, `docker-compose up -d`
 
 # Run the client-side React app in a different terminal window:
 
+Using the template file, you first need to create frontend/.env.
+
 ```sh
 $ cd frontend
 $ npm install