Add databse setup in readme

Author: AlxFrst

Diff for: README.md

@@ -19,10 +19,24 @@ How to use
 3. Run `npm start`
 4. Open your browser at `http://localhost:3000`
 
+Setting up the PostgreSQL database
+----------------------------------
+
+1. Create your database
+2. Create a .env file in the root of the project
+3. Add the following lines to the .env file:
+    DB_USER=YourDatabaseUser
+    DB_PASS=YourDatabasePassword
+    DB_NAME=YourDatabaseName
+    DB_HOST=YourDatabaseHost
+4. Start the application and check if you see the following message in the console:
+    Connected to the PostgreSQL database
+5. If you see the message, you are good to go! ENJYOY
+
 TODO
 ----
 
-- [ ] Add a database
+- [X] Add a database
 - [ ] Add a login system
 
 License