docs: Make instructions about adding "wagtail.contrib.settings" to INSTALLED_APPS more explicit

docs/tutorial/create-footer_for_all_pages.md

@@ -49,7 +49,15 @@ In the preceding code, the `register_setting` decorator registers your `Navigati
 
 Now, migrate your database by running the commands `python manage.py makemigrations` and `python manage.py migrate`. After migrating your database, reload your [admin interface](https://guide.wagtail.org/en-latest/concepts/wagtail-interfaces/#admin-interface). You'll get the error _'wagtailsettings' is not a registered namespace_. This is because you haven't installed the [`wagtail.contrib.settings`](../reference/settings.md) module.
 
-The `wagtail.contrib.settings` module defines models that hold common settings across all your web pages. So, to successfully import the `BaseGenericSetting` and `register_setting`, you must install the `wagtail.contrib.settings` module on your site. To install `wagtail.contrib.settings`, go to your `mysite/settings/base.py` file and add `"wagtail.contrib.settings"` to the `INSTALLED_APPS` list.
+The `wagtail.contrib.settings` module defines models that hold common settings across all your web pages. So, to successfully import the `BaseGenericSetting` and `register_setting`, you must install the `wagtail.contrib.settings` module on your site. To install `wagtail.contrib.settings`, go to your `mysite/settings/base.py` file and add `"wagtail.contrib.settings"` to the `INSTALLED_APPS` list:
+
+```python
+INSTALLED_APPS = [
+    # ...
+    # Add this line to install wagtail.contrib.settings:
+    "wagtail.contrib.settings",
+]
+```
 
 Also, you have to register the _settings_ context processor. Registering _settings_ context processor makes site-wide settings accessible in your templates. To register the _settings_ context processor, modify your `mysite/settings/base.py` file as follows: