[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/text_box.h

@@ -1,11 +1,17 @@
+/**
+ * @file text_box.h
+ * GUI: TextBox view module API
+ */
+
 #pragma once
+
 #include <gui/view.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* TextBox anonymous structure */
+/** TextBox anonymous structure */
 typedef struct TextBox TextBox;
 typedef void (*TextBoxExitCallback)(void* context);
 
@@ -15,46 +21,56 @@ typedef enum {
 } TextBoxFont;
 
 /** Allocate and initialize text_box
+ *
+ * @return     TextBox instance
  */
 TextBox* text_box_alloc();
 
 /** Deinitialize and free text_box
- * @param text_box text_box instance
+ *
+ * @param      text_box  text_box instance
  */
 void text_box_free(TextBox* text_box);
 
 /** Get text_box view
- * @param text_box TextBox instance
- * @return View instance that can be used for embedding
+ *
+ * @param      text_box  TextBox instance
+ *
+ * @return     View instance that can be used for embedding
  */
 View* text_box_get_view(TextBox* text_box);
 
 /** Clean text_box
- * @param text_box TextBox instance
+ *
+ * @param      text_box  TextBox instance
  */
 void text_box_clean(TextBox* text_box);
 
 /** Set text for text_box
- * @param text_box TextBox instance
- * @param text text to set
+ *
+ * @param      text_box  TextBox instance
+ * @param      text      text to set
  */
 void text_box_set_text(TextBox* text_box, const char* text);
 
 /** Set TextBox font
- * @param text_box TextBox instance
- * @param font TextBoxFont instance
+ *
+ * @param      text_box  TextBox instance
+ * @param      font      TextBoxFont instance
  */
 void text_box_set_font(TextBox* text_box, TextBoxFont font);
 
 /** Set text_box context
- * @param text_box TextBox instance
- * @param context context pointer
+ *
+ * @param      text_box  TextBox instance
+ * @param      context   context pointer
  */
 void text_box_set_context(TextBox* text_box, void* context);
 
 /** Set exit callback
- * @param text_box TextBox instance
- * @param callback TextBoxExitCallback callback pointer
+ *
+ * @param      text_box  TextBox instance
+ * @param      callback  TextBoxExitCallback callback pointer
  */
 void text_box_set_exit_callback(TextBox* text_box, TextBoxExitCallback callback);