Updated installation instructions

README.md

@@ -35,7 +35,11 @@ $ npm install
 ```
 
 Name .env.example to .env and ormconfig.json.example to ormconfig.json and add values accordingly
-
+Needed postgresql modules:
+```bash
+# Inside the database that you're connecting to:
+CREATE EXTENSION "uuid-ossp";
+```
 ## Running the app
 
 ```bash