Ready Mode

By giving a mode that signals the pilot is ready other than armed props
at a race event it will be easier to determine when all pilots are ready
to race.

src/main/fc/rc_modes.h

@@ -77,6 +77,7 @@ typedef enum {
     BOXMSPOVERRIDE,
     BOXSTICKCOMMANDDISABLE,
     BOXBEEPERMUTE,
+    BOXREADY,
     CHECKBOX_ITEM_COUNT
 } boxId_e;