Add more documentation for container registry UI

- add more docs
- add additional images

doc/user/packages/container_registry/index.md

@@ -7,6 +7,7 @@
 >   to pass a [personal access token](../../profile/personal_access_tokens.md) instead of your password in order to
 >   login to GitLab's Container Registry.
 > - Multiple level image names support was added in GitLab 9.1.
+> - The group level Container Registry was [introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/23315) in GitLab 12.10.
 
 NOTE: **Note:**
 This document is the user guide. To learn how to enable GitLab Container
@@ -47,11 +48,51 @@ project:
 
 ## Control Container Registry from within GitLab
 
-GitLab offers a simple Container Registry management panel. Go to your project
-and click **Packages > Container Registry** in the project menu.
+GitLab offers a simple Container Registry management panel. This management panel is available
+for both projects and groups.
 
-This view will show you all Docker images in your project and will easily allow you to
-delete them.
+### Control Container Registry for your project
+
+Navigate to your project's **{package}** **Packages > Container Registry**.
+
+![Container Registry project repositories](img/container_registry_repositories_with_quickstart_v12_10.png)
+
+This view will:
+
+- Show all the image repositories that belong to the project.
+- Allow you to [delete](#delete-images-from-within-gitlab) one or more image repository.
+- Allow you to navigate to the image repository details page.
+- Show a **Quick start** dropdown with the most common commands to log in, build and push
+- Optionally, a banner will be visible if the [expiration policy](#expiration-policy) is enabled for this project.
+
+### Control Container Registry for your group
+
+Navigate to your groups's **{package}** **Packages > Container Registry**.
+
+![Container Registry group repositories](img/container_registry_group_repositories_v12_10.png)
+
+This view will:
+
+- Show all the image repositories of the projects that belong to this group.
+- Allow to [delete](#delete-images-from-within-gitlab) one or more image repositories.
+- Allow to navigate to a specific image repository details page.
+
+### Image Repository details page
+
+Clicking on the name of any image repository will navigate to the details.
+
+![Container Registry project repository details](img/container_registry_repository_details_v12.10.png)
+
+NOTE: **Note:**
+The following page has the same functionalities both in the **Group level container registry**
+and in the **Project level container registry**.
+
+This view:
+
+- Shows all the image repository details.
+- Shows all the tags of the image repository.
+- Allows you to quickly copy the tag path (by clicking on the clipboard button near the tag name).
+- Allows you to [delete one or more tags](#delete-images-from-within-gitlab).
 
 ## Use images from GitLab Container Registry