improve readme

README.md

@@ -37,14 +37,19 @@ networks:
   "2b2t": {}
 ```
 
+2. Create the database file:
+```sh
+touch ./data.sqlite
+```
+
 2. Start the containers:
 ```sh
 docker compose up -d
 ```
 
-3. Insert the worker tokens into your master's database.
+3. Insert the worker tokens into your master's database:
 ```sh
-sqlite3 data.sqlite
+sqlite3 ./data.sqlite
 sqlite> INSERT INTO worker (name, token) VALUES ("name", "secret_token");
 sqlite> .exit
 ```