[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/view_port.h

@@ -1,3 +1,8 @@
+/**
+ * @file view_port.h
+ * GUI: ViewPort API
+ */
+
 #pragma once
 
 #include <input/input.h>
@@ -15,50 +20,65 @@ typedef enum {
 } ViewPortOrientation;
 
 /** ViewPort Draw callback
- * @warning called from GUI thread
+ * @warning    called from GUI thread
  */
 typedef void (*ViewPortDrawCallback)(Canvas* canvas, void* context);
 
 /** ViewPort Input callback
- * @warning called from GUI thread
+ * @warning    called from GUI thread
  */
 typedef void (*ViewPortInputCallback)(InputEvent* event, void* context);
 
 /** ViewPort allocator
+ *
  * always returns view_port or stops system if not enough memory.
+ *
+ * @return     ViewPort instance
  */
 ViewPort* view_port_alloc();
 
 /** ViewPort deallocator
+ *
  * Ensure that view_port was unregistered in GUI system before use.
+ *
+ * @param      view_port  ViewPort instance
  */
 void view_port_free(ViewPort* view_port);
 
 /** Set view_port width.
+ *
  * Will be used to limit canvas drawing area and autolayout feature.
- * @param width - wanted width, 0 - auto.
+ *
+ * @param      view_port  ViewPort instance
+ * @param      width      wanted width, 0 - auto.
  */
 void view_port_set_width(ViewPort* view_port, uint8_t width);
 uint8_t view_port_get_width(ViewPort* view_port);
 
 /** Set view_port height.
+ *
  * Will be used to limit canvas drawing area and autolayout feature.
- * @param height - wanted height, 0 - auto.
+ *
+ * @param      view_port  ViewPort instance
+ * @param      height     wanted height, 0 - auto.
  */
 void view_port_set_height(ViewPort* view_port, uint8_t height);
 uint8_t view_port_get_height(ViewPort* view_port);
 
 /** Enable or disable view_port rendering.
- * @param view_port - ViewPort instance
- * @param enabled
- * @warning automatically dispatches update event
+ *
+ * @param      view_port  ViewPort instance
+ * @param      enabled    Indicates if enabled
+ * @warning    automatically dispatches update event
  */
 void view_port_enabled_set(ViewPort* view_port, bool enabled);
 bool view_port_is_enabled(ViewPort* view_port);
 
 /** ViewPort event callbacks
- * @param callback - appropriate callback function
- * @param context - context to pass to callback
+ *
+ * @param      view_port  ViewPort instance
+ * @param      callback   appropriate callback function
+ * @param      context    context to pass to callback
  */
 void view_port_draw_callback_set(ViewPort* view_port, ViewPortDrawCallback callback, void* context);
 void view_port_input_callback_set(
@@ -67,12 +87,17 @@ void view_port_input_callback_set(
     void* context);
 
 /** Emit update signal to GUI system.
+ *
  * Rendering will happen later after GUI system process signal.
+ *
+ * @param      view_port  ViewPort instance
  */
 void view_port_update(ViewPort* view_port);
 
 /** Set ViewPort orientation.
- * @param   orientation, display orientation, horizontal or vertical.
+ *
+ * @param      view_port    ViewPort instance
+ * @param      orientation  display orientation, horizontal or vertical.
  */
 void view_port_set_orientation(ViewPort* view_port, ViewPortOrientation orientation);
 ViewPortOrientation view_port_get_orientation(const ViewPort* view_port);