Add settings for member statuses

app/controllers/admin/settings/membership_controller.rb

@@ -0,0 +1,23 @@
+class Admin::Settings::MembershipController < Admin::SettingsController
+  def show
+  end
+
+  def update
+    update_settings
+
+    redirect_to admin_settings_membership_path, flash: {
+      success: "Settings saved"
+    }
+  end
+
+  private
+
+    def setting_params
+      params.require(:setting).permit([
+        :member_status_contributor,
+        :member_status_sustainer,
+        :user_index_show_contributors,
+        :user_index_show_sustainers
+      ])
+    end
+end