Fixed typo in Z Probe and Endstop section.

Marlin/Configuration.h

@@ -484,7 +484,7 @@ const bool Z_MAX_ENDSTOP_INVERTING = false; // set to true to invert the logic o
 
   #endif
 
-// If you have are a Z Probe in addition to endstop(s) for Z Homing, uncomment the #define Z_PROBE_AND_ENDSTOP line below and configure Z Probe settings.
+// If you have a Z Probe in addition to endstop(s) for Z Homing, uncomment the #define Z_PROBE_AND_ENDSTOP line below and configure Z Probe settings.
 // Only use this if you have both a Z PROBE and Z HOMING ENDSTOP(S). If you are using Z_SAFE_HOMING above, then you probably don't need this unless you want to make use of
 // a non-default pin for your Z Probe.
 // Note: It's expected that your Z Probe triggers in the direction towards your bed. If your Z Probe does not trigger when traveling towards you bed, it will trigger when it's moving