Refactor and restructure environments page

- Groups content into relevant sections.
- Content edited.

doc/ci/environments/protected_environments.md

 # Protected Environments **[PREMIUM]**
 
-> [Introduced][6303] in [GitLab Premium][ee] 11.3.
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6303) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.3.
 
 ## Overview
 
-[Environments](../environments.md) can be used for different scopes, some of
-them are just for testing while others are for production. As deploy jobs could
-be raised by different users with different roles, it is very important that
-specific environments are "protected" to avoid unauthorized people to affect them.
+[Environments](../environments.md) can be used for different reasons:
+
+- Some of them are just for testing.
+- Others are for production.
+
+Because deploy jobs can be raised by different users with different roles, it is important that
+specific environments are "protected" to avoid unauthorized people affecting them.
 
 By default, a protected environment does one thing: it ensures that only people
 with the right privileges can deploy to it, thus keeping it safe.
@@ -18,31 +21,28 @@ A GitLab admin is always allowed to use environments, even if they are protected
 To protect, update, or unprotect an environment, you need to have at least
 [Maintainer permissions](../../user/permissions.md).
 
-## Configuring protected environments
+## Protecting environments
 
 To protect an environment:
 
-1. Navigate to your project's **Settings ➔ CI/CD**.
-1. Scroll to find the **Protected Environments** section.
-1. From the **Environment** dropdown menu, select the environment you want to protect and
-   click **Protect**.
-1. In the "Allowed to Deploy" dropdown menu, you can select the role and/or the
-   users and/or the groups you want to have deploy access. There are some
-   considerations to have in mind:
+1. Navigate to your project's **Settings > CI/CD**.
+1. Expand the **Protected Environments** section.
+1. From the **Environment** dropdown menu, select the environment you want to protect.
+1. In the **Allowed to Deploy** dropdown menu, select the role, users, or  groups you want to have deploy access.
+   There are some considerations to have in mind:
     - There are two roles to choose from:
       - **Maintainers**: will allow access to all maintainers in the project.
       - **Developers**: will allow access to all maintainers and all developers in the project.
     - You can only select groups that are associated with the project.
     - Only users that have at least Developer permission level will appear on
-      the "Allowed to Deploy" dropdown menu.
+      the **Allowed to Deploy** dropdown menu.
+1. Click the **Protect** button.
+
+The protected environment will now appear in the list of protected environments.
 
-1. Once done, the protected environment will appear in the "Protected Environments"
-   list.
+## Modifying and unprotecting environments
 
-Maintainers can update existing protected environments at any time
-by changing the access on "Allowed to Deploy" dropdown menu. Similarly,
-to unprotect a protected environment, Maintainers need to click the
-**Unprotect** button of the respective environment.
+Maintainers can:
 
-[ee]: https://about.gitlab.com/pricing/
-[6303]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6303
+- Update existing protected environments at any time by changing the access on **Allowed to deploy** dropdown menu.
+- Unprotect a protected environment by clicking the **Unprotect** button of the environment to unprotect.