add support for hid gamepad interface

add documentation for HID joystick
Add joystick_task to read analog axes values even when no key is pressed or release. update doc
Update docs/feature_joystick.md
Manage pin setup and read to maintain matrix scan after analog read

quantum/joystick.c

@@ -0,0 +1,11 @@
+#include "joystick.h"
+
+joystick_t joystick_status = { 
+  .buttons = {0},
+  .axes = {0},
+  .status = 0
+};
+
+//array defining the reading of analog values for each axis
+__attribute__ ((weak))
+joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {};