Add missing german translations.

Marlin/language_de.h

@@ -152,6 +152,16 @@
 #define MSG_HEATING_COMPLETE                "Aufgeheizt"
 #define MSG_BED_HEATING                     "Bett aufheizen"
 #define MSG_BED_DONE                        "Bett aufgeheizt"
+#define MSG_EXTRUDE                         "Extrudieren"
+#define MSG_BED_Z                           "Bett Z"
+#define MSG_A_TRAVEL                        "A Rueckzug"
+#define MSG_HEATING_FAILED_LCD              "Heizen fehlgesch."
+#define MSG_ERR_REDUNDANT_TEMP              "Redund. Temperaturabw."
+#define MSG_THERMAL_RUNAWAY                 "Temp. n. erreicht"
+#define MSG_ERR_MAXTEMP                     "Temp. ueberschritten"
+#define MSG_ERR_MAXTEMP                     "Temp. unterschritten"
+#define MSG_ERR_MAXTEMP_BED                 "Temp. Bett ueberschr."
+#define MSG_ERR_MAXTEMP_BED                 "Temp. Bett unterschr."
 
 #if ENABLED(DELTA_CALIBRATION_MENU)
   #define MSG_DELTA_CALIBRATE               "Delta kalibrieren"