Add muli-languages support for Ventoy menu.

F5 ---> Menu Language Select
Language files are in INSTALL/grub/menu/ directory.

LANGUAGES/check.sh

@@ -8,10 +8,23 @@ fi
 
 gcc -DFOR_VTOY_JSON_CHECK $VTOY_PATH/Ventoy2Disk/Ventoy2Disk/VentoyJson.c -I $VTOY_PATH/Ventoy2Disk/Ventoy2Disk/ -o checkjson
 
+RET=0
+
 ./checkjson $VTOY_PATH/LANGUAGES/languages.json
 ret=$?
+if [ $ret -eq 0 ]; then
+    for i in $(ls $VTOY_PATH/INSTALL/grub/menu); do
+        ./checkjson $VTOY_PATH/INSTALL/grub/menu/$i
+        ret=$?
+        if [ $ret -ne 0 ]; then
+            echo "INSTALL/grub/menu/$i invalid json format"
+            break
+        fi
+    done
+else
+    echo "languages.json invalid json format"
+fi
 
 rm -f ./checkjson
 [ $ret -eq 0 ]
 
-