Note the danger of using approvals_before_merge attribute in the project resource

Closes: #969

Author: timofurrer

docs/resources/project.md

@@ -75,6 +75,9 @@ resource "gitlab_project" "peters_repo" {
 - `allow_merge_on_skipped_pipeline` (Boolean) Set to true if you want to treat skipped pipelines as if they finished with success.
 - `analytics_access_level` (String) Set the analytics access level. Valid values are `disabled`, `private`, `enabled`.
 - `approvals_before_merge` (Number) Number of merge request approvals required for merging. Default is 0.
+  This field **does not** work well in combination with the `gitlab_project_approval_rule` resource
+  and is most likely gonna be deprecated in a future GitLab version (see [this upstream epic](https://gitlab.com/groups/gitlab-org/-/epics/7572)).
+  In the meantime we recommend against using this attribute and use `gitlab_project_approval_rule` instead.
 - `archive_on_destroy` (Boolean) Set to `true` to archive the project instead of deleting on destroy. If set to `true` it will entire omit the `DELETE` operation.
 - `archived` (Boolean) Whether the project is in read-only mode (archived). Repositories can be archived/unarchived by toggling this parameter.
 - `auto_cancel_pending_pipelines` (String) Auto-cancel pending pipelines. This isn’t a boolean, but enabled/disabled.

internal/provider/resource_gitlab_project.go

@@ -106,10 +106,14 @@ var resourceGitLabProjectSchema = map[string]*schema.Schema{
 		Default:     true,
 	},
 	"approvals_before_merge": {
-		Description: "Number of merge request approvals required for merging. Default is 0.",
-		Type:        schema.TypeInt,
-		Optional:    true,
-		Default:     0,
+		Description: `Number of merge request approvals required for merging. Default is 0.
+  This field **does not** work well in combination with the ` + "`gitlab_project_approval_rule`" + ` resource
+  and is most likely gonna be deprecated in a future GitLab version (see [this upstream epic](https://gitlab.com/groups/gitlab-org/-/epics/7572)).
+  In the meantime we recommend against using this attribute and use ` + "`gitlab_project_approval_rule`" + ` instead.
+`,
+		Type:     schema.TypeInt,
+		Optional: true,
+		Default:  0,
 	},
 	"wiki_enabled": {
 		Description: "Enable wiki for the project.",