Split updates to settings.py into distinct items

Author: bcopy

en/django_start_project/README.md

@@ -139,9 +139,13 @@ ALLOWED_HOSTS = ['127.0.0.1', '.pythonanywhere.com']
 >     {% filename %}mysite/settings.py{% endfilename %}
 >     ```python
 >     SECRET_KEY = os.getenv('SECRET')
->     # and a little further, we inject the name of your new Glitch website ...
+>     ```
+>   * And a little further, in the same file, we inject the name of your new Glitch website :
+>     {% filename %}mysite/settings.py{% endfilename %}
+>     ```python
 >     ALLOWED_HOSTS = [os.getenv('PROJECT_DOMAIN') + ".glitch.me"]
 >     ```
+>     The PROJECT_DOMAIN value is automatically generated by Glitch, it will correspond to the name of your project.
 
 ## Set up a database