[ion] big cleanup

ion/include/ion.h

@@ -4,7 +4,13 @@
 #include <ion/framebuffer.h>
 #include <ion/keyboard.h>
 
-void ion_init();
+/* ION is not your regular library. It is a library you link against, but it
+ * will take care of configuring the whole environment for you. In POSIX terms,
+ * ION will implement the "main" function.
+ * Don't worry though, once all its initialization will be performed, ION will
+ * jump to your code at ion_app, which you have to implement yourself. */
+
+void ion_app();
 
 void ion_display_on();
 void ion_display_off();