update README

Author: yumafuu

README.md

@@ -44,13 +44,46 @@ Set environment variables:
 ## Usage
 
 ```hcl
+resource "github_repository_ruleset" "example" {
+  name        = "example-ruleset"
+  repository  = "repo"
+  target      = "branch"
+  enforcement = "active"
+
+  conditions {
+    ref_name {
+      include = ["~DEFAULT_BRANCH"]
+      exclude = []
+    }
+  }
+
+  rules {
+    pull_request {
+      required_approving_review_count   = 1
+      dismiss_stale_reviews_on_push     = true
+      require_code_owner_review         = true
+      require_last_push_approval        = false
+      required_review_thread_resolution = false
+    }
+  }
+}
+
 resource "kwgithub_ruleset_allowed_merge_methods" "example" {
   repository = "repo"
-  ruleset_id = "123456"
+  ruleset_id = github_repository_ruleset.example.ruleset_id
   allowed_merge_methods = ["merge", "squash"]
+
+  # Recommended: GitHub resets allowed_merge_methods when ruleset is updated
+  force_update = timestamp()
+
+  depends_on = [github_repository_ruleset.example]
 }
 ```
 
+### ⚠️Important: Force Update Recommendation
+
+It is strongly recommended to include `force_update = timestamp()` in your resource configuration. This ensures the resource is updated on every Terraform run, which is necessary because GitHub's API specification causes `allowed_merge_methods` to be reset whenever `github_repository_ruleset` is updated. Without `force_update`, your merge method configuration may be unexpectedly lost when other ruleset changes are applied.
+
 ## Why This Provider?
 
 The official GitHub provider resets `allowed_merge_methods` when updating other ruleset rules. This provider automatically detects and restores the expected configuration.