Add doxygen docs

include/sta/fifo_buffer.hpp

@@ -1,3 +1,7 @@
+/**
+ * @file
+ * @brief FIFO buffer type.
+ */
 #ifndef STA_FIFO_BUFFER_HPP
 #define STA_FIFO_BUFFER_HPP
 
@@ -9,6 +13,8 @@ namespace sta
 	 *
 	 * @tparam Size     Size type
 	 * @tparam N        Buffer size
+	 *
+	 * @ingroup staCore
 	 */
 	template <typename Size, Size N>
 	class FifoBuffer