[FL-1906] Documentation: add Doxyfile, prepare sources for doxygen. (#741)

* Documentation: add Doxyfile, prepare sources for doxygen.

* Update ReadMe and remove obsolete CLA

* Add contribution guide

* Contributing: update text

* Correct spelling

applications/gui/modules/variable-item-list.h

@@ -1,4 +1,10 @@
+/**
+ * @file variable-item-list.h
+ * GUI: VariableItemList view module API
+ */
+
 #pragma once
+
 #include <gui/view.h>
 
 #ifdef __cplusplus
@@ -11,29 +17,40 @@ typedef void (*VariableItemChangeCallback)(VariableItem* item);
 typedef void (*VariableItemListEnterCallback)(void* context, uint32_t index);
 
 /** Allocate and initialize VariableItemList
- * @return VariableItemList* 
+ *
+ * @return     VariableItemList*
  */
 VariableItemList* variable_item_list_alloc();
 
 /** Deinitialize and free VariableItemList
- * @param variable_item_list VariableItemList instance
+ *
+ * @param      variable_item_list  VariableItemList instance
  */
 void variable_item_list_free(VariableItemList* variable_item_list);
 
 /** Clear all elements from list
- * @param variable_item_list VariableItemList instance
+ *
+ * @param      variable_item_list  VariableItemList instance
  */
 void variable_item_list_clean(VariableItemList* variable_item_list);
 
+/** Get VariableItemList View instance
+ *
+ * @param      variable_item_list  VariableItemList instance
+ *
+ * @return     View instance
+ */
 View* variable_item_list_get_view(VariableItemList* variable_item_list);
 
 /** Add item to VariableItemList
- * @param variable_item_list VariableItemList instance
- * @param label item name
- * @param values_count item values count
- * @param change_callback called on value change in gui
- * @param context item context
- * @return VariableItem* item instance
+ *
+ * @param      variable_item_list  VariableItemList instance
+ * @param      label               item name
+ * @param      values_count        item values count
+ * @param      change_callback     called on value change in gui
+ * @param      context             item context
+ *
+ * @return     VariableItem* item instance
  */
 VariableItem* variable_item_list_add(
     VariableItemList* variable_item_list,
@@ -43,9 +60,10 @@ VariableItem* variable_item_list_add(
     void* context);
 
 /** Set enter callback
- * @param variable_item_list VariableItemList instance
- * @param calback VariableItemListEnterCallback instance
- * @param context pointer to context
+ *
+ * @param      variable_item_list  VariableItemList instance
+ * @param      callback            VariableItemListEnterCallback instance
+ * @param      context             pointer to context
  */
 void variable_item_list_set_enter_callback(
     VariableItemList* variable_item_list,
@@ -53,29 +71,35 @@ void variable_item_list_set_enter_callback(
     void* context);
 
 /** Set item current selected index
- * @param item VariableItem* instance
- * @param current_value_index 
+ *
+ * @param      item                 VariableItem* instance
+ * @param      current_value_index  The current value index
  */
 void variable_item_set_current_value_index(VariableItem* item, uint8_t current_value_index);
 
 /** Set item current selected text
- * @param item VariableItem* instance
- * @param current_value_text 
+ *
+ * @param      item                VariableItem* instance
+ * @param      current_value_text  The current value text
  */
 void variable_item_set_current_value_text(VariableItem* item, const char* current_value_text);
 
 /** Get item current selected index
- * @param item VariableItem* instance
- * @return uint8_t current selected index
+ *
+ * @param      item  VariableItem* instance
+ *
+ * @return     uint8_t current selected index
  */
 uint8_t variable_item_get_current_value_index(VariableItem* item);
 
 /** Get item context
- * @param item VariableItem* instance
- * @return void* item context
+ *
+ * @param      item  VariableItem* instance
+ *
+ * @return     void* item context
  */
 void* variable_item_get_context(VariableItem* item);
 
 #ifdef __cplusplus
 }
-#endif
+#endif