adds widget explanations

src/widget/widget.h

@@ -1,6 +1,11 @@
 /* SPDX-License-Identifier: MIT */
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
+/* Header collector. 
+   It exports all the header files from this directory. 
+   Just include <widget.h> in the file in order to use all functionality 
+   given by this directory. */
+
 #ifndef WIDGET_H
 #define WIDGET_H
 #include "app.h"

src/widget_core/widget_core.c

@@ -1,6 +1,10 @@
 /* SPDX-License-Identifier: MIT */
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
+/* WidgetCore is a base for all widgets.
+  It is used by widgets themselves and some core components,
+  so it is separated from the widget directory */
+
 #include "widget_core.h"
 #include "../main.h"
 #include <ncursesw/ncurses.h>