Update django-postgresql-docker.md

Author: jAniceto

programming-notes/python/django/django-postgresql-docker.md

@@ -243,7 +243,7 @@ docker exec -ti django_app postgres_db psql -U username -d demo_db
 or to access the Django shell:
 
 ```bash
-docker exec -ti django_app manage.py shell
+docker exec -ti django_app python manage.py shell
 ```
 
 
@@ -288,4 +288,4 @@ docker-compose up
 
 - [How to Dockerize a Django App: Step-by-Step Guide for Beginners](https://www.docker.com/blog/how-to-dockerize-django-app/)
 
-- [Dockerizing Django with Postgres, Gunicorn, and Nginx](https://testdriven.io/blog/dockerizing-django-with-postgres-gunicorn-and-nginx/)
+- [Dockerizing Django with Postgres, Gunicorn, and Nginx](https://testdriven.io/blog/dockerizing-django-with-postgres-gunicorn-and-nginx/)