Improved grouping and allow doxygen without other defines

include/sta/tacos/manager.hpp

@@ -11,7 +11,7 @@
 
 #include <sta/config.hpp>
 
-#ifndef STA_TACOS_MANAGER_PRIORITY
+#if !defined(STA_TACOS_MANAGER_PRIORITY)  && !defined(DOXYGEN)
 #	error "Manger task priority not specified in config.hpp"
 #else 
 
@@ -40,6 +40,8 @@ namespace sta
 		public:
 			/**
 			 * @brief Get the singleton instance of the manager.
+			 * 
+			 * @ingroup tacos_manager
 			 */
 			static Manager* instance()
 			{