Added thermistor 60 to configuration.h

Marlin/Configuration.h

@@ -125,6 +125,7 @@
 // 8 is 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup)
 // 9 is 100k GE Sensing AL03006-58.2K-97-G1 (4.7k pullup)
 // 10 is 100k RS thermistor 198-961 (4.7k pullup)
+// 60 is 100k Maker's Tool Works Kapton Bed Thermister
 //
 //    1k ohm pullup tables - This is not normal, you would have to have changed out your 4.7k for 1k
 //                          (but gives greater accuracy and more stable PID)