resource/gitlab_project_mirror: Improve documentation and reference upstream docs

Author: timofurrer

docs/resources/project_mirror.md

@@ -3,22 +3,20 @@
 page_title: "gitlab_project_mirror Resource - terraform-provider-gitlab"
 subcategory: ""
 description: |-
-  This resource allows you to add a mirror target for the repository, all changes will be synced to the remote target.
-  -> This is for pushing changes to a remote repository. Pull Mirroring can be configured using a combination of the
-  import_url, mirror, and mirror_trigger_builds properties on the gitlab_project resource.
-  For further information on mirroring, consult the
-  gitlab documentation https://docs.gitlab.com/ee/user/project/repository/repository_mirroring.html#repository-mirroring.
+  The gitlab_project_mirror resource allows to manage the lifecycle of a project mirror.
+  This is for pushing changes to a remote repository. Pull Mirroring can be configured using a combination of the
+  importurl, mirror, and mirrortriggerbuilds properties on the gitlabproject resource.
+  Upstream API: GitLab REST API docs https://docs.gitlab.com/ee/api/remote_mirrors.html
 ---
 
 # gitlab_project_mirror (Resource)
 
-This resource allows you to add a mirror target for the repository, all changes will be synced to the remote target.
+The `gitlab_project_mirror` resource allows to manage the lifecycle of a project mirror.
 
--> This is for *pushing* changes to a remote repository. *Pull Mirroring* can be configured using a combination of the
-`import_url`, `mirror`, and `mirror_trigger_builds` properties on the `gitlab_project` resource.
+This is for *pushing* changes to a remote repository. *Pull Mirroring* can be configured using a combination of the
+import_url, mirror, and mirror_trigger_builds properties on the gitlab_project resource.
 
-For further information on mirroring, consult the
-[gitlab documentation](https://docs.gitlab.com/ee/user/project/repository/repository_mirroring.html#repository-mirroring).
+**Upstream API**: [GitLab REST API docs](https://docs.gitlab.com/ee/api/remote_mirrors.html)
 
 ## Example Usage
 

internal/provider/resource_gitlab_project_mirror.go

@@ -14,11 +14,12 @@ import (
 
 var _ = registerResource("gitlab_project_mirror", func() *schema.Resource {
 	return &schema.Resource{
-		Description: "This resource allows you to add a mirror target for the repository, all changes will be synced to the remote target.\n\n" +
-			"-> This is for *pushing* changes to a remote repository. *Pull Mirroring* can be configured using a combination of the\n" +
-			"`import_url`, `mirror`, and `mirror_trigger_builds` properties on the `gitlab_project` resource.\n\n" +
-			"For further information on mirroring, consult the\n" +
-			"[gitlab documentation](https://docs.gitlab.com/ee/user/project/repository/repository_mirroring.html#repository-mirroring).",
+		Description: `The ` + "`" + `gitlab_project_mirror` + "`" + ` resource allows to manage the lifecycle of a project mirror.
+
+This is for *pushing* changes to a remote repository. *Pull Mirroring* can be configured using a combination of the
+import_url, mirror, and mirror_trigger_builds properties on the gitlab_project resource.
+
+**Upstream API**: [GitLab REST API docs](https://docs.gitlab.com/ee/api/remote_mirrors.html)`,
 
 		CreateContext: resourceGitlabProjectMirrorCreate,
 		ReadContext:   resourceGitlabProjectMirrorRead,