Spelling correction

Author: Fahad

src/Stepper.cpp

@@ -378,7 +378,7 @@ void Stepper::stepMotor(int thisStep)
 
 /*
  * Allow powering down all coils after stepping, 
- * to reduce heat, power and allow manuall rotation.
+ * to reduce heat, power and allow manual rotation.
  */
 void Stepper::idelAfterStep(bool idle)
 {

src/Stepper.h

@@ -96,7 +96,7 @@ class Stepper {
     // mover method:
     void step(int number_of_steps);
 
-    // Power down all coils after stepping, to reduce heat, power and allow manuall rotation.
+    // Power down all coils after stepping, to reduce heat, power and allow manual rotation.
     void idelAfterStep(bool idle);
 
     int version(void);