docs: Project collaboration mode docs (#3360)

frontend/src/component/project/Project/ProjectForm/CollaborationModeTooltip.tsx

@@ -25,7 +25,8 @@ export const CollaborationModeTooltip: FC = () => (
                 <Box sx={{ mt: 2 }}>
                     <StyledTitle>protected: </StyledTitle>
                     <StyledDescription>
-                        only project members can submit change requests
+                        Only admins and project members can submit change
+                        requests
                     </StyledDescription>
                 </Box>
             </>

website/docs/reference/project-collaboration-mode.md

@@ -0,0 +1,45 @@
+---
+title: Project collaboration mode
+---
+
+:::info Availability
+
+The project collaboration mode is an enterprise-only feature that was introduced in **Unleash 4.22.0**.
+
+:::
+
+A project's **collaboration mode** specifies **who can submit [change requests](change-requests.md)**. There are two collaboration modes:
+- [**open**](#open-collaboration-mode)
+- [**protected**](#protected-collaboration-mode)
+
+## **Open** collaboration mode
+
+Anyone can submit change requests in an **open** project, regardless of their permissions within the project and globally. This is the default collaboration mode for projects.
+
+The open collaboration mode is the default in Unleash and is how all projects worked in Unleash before the introduction of collaboration modes.
+
+## **Protected** collaboration mode
+
+Only admins and project members can submit change requests in a **protected** project. Other users can not submit change requests.
+
+### Change requests
+
+When you change a project's collaboration mode from open to protected, users who do not have the right permissions will lose the ability to create new change requests.
+
+However, existing change requests created by these users will not be deleted. Any users with open change requests will still be able to cancel the change request, but they will **not** be able to update the change request.
+
+## Project collaboration mode setting
+
+You can set a project's collaboration mode when you create a project and at any point after creation.
+
+![Project creation form with a collaboration mode field and corresponding explanation.](/img/collaboration-mode.png)
+Because the project's collaboration mode is a core part of the project, the controls to change it are available on the "edit project" page.
+
+![The project-level header section with the "edit project" button highlighted.](/img/edit-project.png)
+
+## Pre-existing projects
+
+Projects that were created in earlier versions of Unleash (before the release of project collaboration modes) get the **open** mode when they are migrated to a version of Unleash with project collaboration modes.
+
+To change the project collaboration mode for an existing project you have to edit the project.
+