resource/gitlab_user: Improve documentation and reference upstream docs

Author: timofurrer

docs/resources/user.md

@@ -3,17 +3,21 @@
 page_title: "gitlab_user Resource - terraform-provider-gitlab"
 subcategory: ""
 description: |-
-  This resource allows you to create and manage GitLab users.
-  Note your provider will need to be configured with admin-level access for this resource to work.
+  The gitlab_user resource allows to manage the lifecycle of a user.
+  -> the provider needs to be configured with admin-level access for this resource to work.
   -> You must specify either password or reset_password.
+  Upstream API: GitLab REST API docs https://docs.gitlab.com/ee/api/users.html
 ---
 
 # gitlab_user (Resource)
 
-This resource allows you to create and manage GitLab users.
-Note your provider will need to be configured with admin-level access for this resource to work.
+The `gitlab_user` resource allows to manage the lifecycle of a user.
 
--> You must specify either `password` or `reset_password`.
+-> the provider needs to be configured with admin-level access for this resource to work.
+
+-> You must specify either password or reset_password.
+
+**Upstream API**: [GitLab REST API docs](https://docs.gitlab.com/ee/api/users.html)
 
 ## Example Usage
 

internal/provider/resource_gitlab_user.go

@@ -22,9 +22,13 @@ var validUserStateValues = []string{
 
 var _ = registerResource("gitlab_user", func() *schema.Resource {
 	return &schema.Resource{
-		Description: "This resource allows you to create and manage GitLab users.\n" +
-			"Note your provider will need to be configured with admin-level access for this resource to work.\n\n" +
-			"-> You must specify either `password` or `reset_password`.",
+		Description: `The ` + "`gitlab_user`" + ` resource allows to manage the lifecycle of a user.
+
+-> the provider needs to be configured with admin-level access for this resource to work.
+
+-> You must specify either password or reset_password.
+
+**Upstream API**: [GitLab REST API docs](https://docs.gitlab.com/ee/api/users.html)`,
 
 		CreateContext: resourceGitlabUserCreate,
 		ReadContext:   resourceGitlabUserRead,