Update language_it.h

ADD missing translation

Marlin/language_it.h

@@ -151,6 +151,19 @@
 #define MSG_ENDSTOP_ABORT                   "Finecorsa abort"
 #define MSG_END_HOUR                        "ore"
 #define MSG_END_MINUTE                      "minuti"
+#define MSG_BED_Z                           "piatto Z"
+#define MSG_A_TRAVEL                        "A-Spostamento"
+#define MSG_HEATING_FAILED_LCD              "Riscald. Fallito"
+#define MSG_ERR_REDUNDANT_TEMP              "Err: TERM RINDONDANTI"
+#define MSG_THERMAL_RUNAWAY                 "SURRISCALDAMENTO"
+#define MSG_ERR_MAXTEMP                     "Err: TEMP MAX"
+#define MSG_ERR_MINTEMP                     "Err: TEMP MIN"
+#define MSG_ERR_MAXTEMP_BED                 "Err: TMAX PIATTO"
+#define MSG_ERR_MINTEMP_BED                 "Err: TMIN PIATTO"
+#define MSG_HEATING                         "Riscaldamento.."
+#define MSG_HEATING_COMPLETE                "Riscald completo"
+#define MSG_BED_HEATING                     "Risc. Piatto.."
+#define MSG_BED_DONE                        "Risc. Piatto Completo"
 
 #if ENABLED(DELTA_CALIBRATION_MENU)
   #define MSG_DELTA_CALIBRATE               "Calibraz. Delta"