Remove thunder_demo module

* Remove thunder_demo module

* Update docs

---------

Co-authored-by: Christian Fritsch <[email protected]>

composer.json

@@ -57,7 +57,6 @@
         "drupal/config_update": "^1.7 || ^2.0",
         "drupal/content_lock": "^2.1",
         "drupal/crop": "^2.2",
-        "drupal/default_content": "^1.0-alpha7||^2.0@ALPHA",
         "drupal/diff": "1.7",
         "drupal/dropzonejs": "^2.8",
         "drupal/empty_fields": "^1.0-alpha1",

docs/README.md

@@ -50,9 +50,6 @@ Public License to further enhance Thunder.
 * **Mobile Friendly**: With the Thunder installation, you get a responsive theme for frontend and backend. When writing
   an article, you can check how your text will look on different smartphones and tablets with the help of the device
   preview.
-* **Demo Content and Guided Tour**: We added demo content and a guided tour to make it easier for newcomers to
-  understand how Thunder works. Step by step, we explain how to add an article, how to edit an article, or how to add
-  and sort channels.
 * **Flexible System**: With Thunder, you get a system with a very high scalability. It's extendable with more than 2500
   modules to fit every need. Plus, it's themeable.
 * **Big Drupal community**: Benefit from an active community with more than 100.000 user actively contributing and more

docs/developer-guide/migration/migrate-7-8.md

@@ -31,9 +31,15 @@ drush updb
 You should at least see the Thunder XXXX schema update. If not, double check that the correct version of Thunder
 is installed, and that `drush updb` did not throw any errors.
 
-Before you start with the code and database update please disable the jQuery UI Draggable module or require it on your own.
+In this release, we have removed a couple of modules from the Thunder distribution. If you use one or more of these
+modules you have to require them manually. The following modules have been removed:
+
+- [jQuery UI Draggable](https://www.drupal.org/project/jquery_ui_draggable)
+- [Default content](https://www.drupal.org/project/default_content)
+
+To require these modules, run the following commands:
 
 ```bash
 composer require drupal/jquery_ui_draggable
+composer require drupal/default_content
 ```
-