Add Requirements documentation

Adds Requirements feature documentation under
user docs.

doc/user/project/index.md

@@ -102,6 +102,7 @@ When you create a project in GitLab, you'll have access to a large number of
 - [Code owners](code_owners.md): specify code owners for certain files **(STARTER)**
 - [License Compliance](../compliance/license_compliance/index.md): approve and blacklist licenses for projects. **(ULTIMATE)**
 - [Dependency List](../application_security/dependency_list/index.md): view project dependencies. **(ULTIMATE)**
+- [Requirements](requirements/index.md): Requirements allow you to create criteria to check your products against. **(ULTIMATE)**
 
 ### Project integrations
 

doc/user/project/requirements/index.md

+---
+type: reference, howto
+---
+
+# Requirements **(ULTIMATE)**
+
+> [Introduced](https://gitlab.com/groups/gitlab-org/-/epics/2703) in [GitLab Ultimate](https://about.gitlab.com/pricing/) 12.10.
+
+Requirements allow you to create criteria to check your products against. They
+can be based on users, stakeholders, system, software, or anything else you
+find important to capture.
+
+![requirements list view](img/requirements_list_view_v12_10.png)
+
+## Create a requirement
+
+A paginated list of requirements is available in each project, and there you
+can create a new requirement.
+
+To create a requirement:
+
+1. From your project page, go to **{requirements}** **Requirements**.
+1. Click **New requirement**.
+1. Enter a descriptive title and click **Create requirement**.
+
+You will see the newly created requirement on the top of the list, as the requirements
+list is sorted by creation date in descending order.
+
+![requirement create view](img/requirement_create_view_v12_10.png)
+
+## Edit a requirement
+
+You can edit a requirement (if you have the necessary privileges) from the requirements
+list page.
+
+To edit a requirement:
+
+1. From the requirements list, click the **Edit** (**{pencil}**) button.
+1. Update the title in text input field.
+1. Click **Save changes**.
+
+![requirement edit view](img/requirement_edit_view_v12_10.png)
+
+The requirements list shows the new title immediately.
+
+![requirement edit saved](img/requirement_edit_save_v12_10.png)
+
+## Archive a requirement
+
+You can archive an open requirement (if you have the necessary privileges) while
+you're in the **Open** tab.
+
+From the requirements list page, click the **Archive** (**{archive}**) button.
+
+![requirement archive view](img/requirement_archive_view_v12_10.png)
+
+As soon as a requirement is archived, it no longer appears in the **Open** tab.
+
+## Reopen a requirement
+
+You can view the list of archived requirements in the **Archived** tab.
+
+![archived requirements list](img/requirements_archived_list_view_v12_10.png)
+
+To reopen an archived requirement, click the **Reopen** button.
+
+As soon as a requirement is reopened, it no longer appears in the **Archived** tab.