Update docs for Terraform state API permissions

doc/user/infrastructure/index.md

@@ -36,6 +36,14 @@ To get started with a GitLab-managed Terraform State, there are two different op
 - [Use a local machine](#get-started-using-local-development).
 - [Use GitLab CI](#get-started-using-gitlab-ci).
 
+## Permissions for using Terraform
+
+In GitLab version 13.1, [Maintainer access](../permissions.md) was required to use a
+GitLab managed Terraform state backend. In GitLab versions 13.2 and greater,
+[Maintainer access](../permissions.md) is required to lock, unlock and write to the state
+(using `terraform apply`), while [Developer access](../permissions.md) is required to read
+the state (using `terraform plan -lock=false`).
+
 ## Get started using local development
 
 If you plan to only run `terraform plan` and `terraform apply` commands from your
@@ -54,8 +62,7 @@ local machine, this is a simple way to get started:
    ```
 
 1. Create a [Personal Access Token](../profile/personal_access_tokens.md) with
-   the `api` scope. The Terraform backend is restricted to users with
-   [Maintainer access](../permissions.md) to the repository.
+   the `api` scope.
 
 1. On your local machine, run `terraform init`, passing in the following options,
    replacing `<YOUR-PROJECT-NAME>`, `<YOUR-PROJECT-ID>`,  `<YOUR-USERNAME>` and
@@ -89,10 +96,6 @@ Next, [configure the backend](#configure-the-backend).
 After executing the `terraform init` command, you must configure the Terraform backend
 and the CI YAML file:
 
-CAUTION: **Important:**
-The Terraform backend is restricted to users with [Maintainer access](../permissions.md)
-to the repository.
-
 1. In your Terraform project, define the [HTTP backend](https://www.terraform.io/docs/backends/types/http.html)
    by adding the following code block in a `.tf` file (such as `backend.tf`) to
    define the remote backend:

doc/user/permissions.md

@@ -142,6 +142,8 @@ The following table depicts the various user permission levels in a project.
 | Manage clusters                                   |         |            |             | ✓        | ✓      |
 | Manage Project Operations                         |         |            |             | ✓        | ✓      |
 | View Pods logs                                    |         |            |             | ✓        | ✓      |
+| Read Terraform state                              |         |            | ✓           | ✓        | ✓      |
+| Manage Terraform state                            |         |            |             | ✓        | ✓      |
 | Manage license policy **(ULTIMATE)**              |         |            |             | ✓        | ✓      |
 | Edit comments (posted by any user)                |         |            |             | ✓        | ✓      |
 | Manage Error Tracking                             |         |            |             | ✓        | ✓      |