Added doxgen comments to filesyste, checkbox, numupdown and screen module. And some minor changes to the other modules.

common/lowlevel/ll_touch.h

@@ -1,6 +1,23 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+/**
+ * @addtogroup lowlevel
+ */
+/*@{*/
+
+/**
+ * @defgroup ll_touch Touch (LowLevel)
+ * Low level functions for the \ref touch module
+ */
+/*@}*/
+
+/**
+ * @addtogroup ll_touch
+ */
+/*@{*/
+
+
 bool ll_touch_init();
 
-
+/*@}*/