Fix Height conversion and update DateTime comment

- Update the comment for DateTime() to accurately describe its functionality
- Fix the Height conversion (CentiMeter and MilliMeter) calculations by changing the division to multiplication

This commit ensures that the conversion functions work as intended and improves the description for DateTime().

height.go

@@ -20,8 +20,7 @@ func (h Height) IsAvailable() bool {
 	return !h.na
 }
 
-// DateTime returns true if an Height value was
-// available at time of query
+// DateTime returns the timestamp associated with the Height value
 func (h Height) DateTime() time.Time {
 	return h.dt
 }
@@ -64,7 +63,7 @@ func (h Height) CentiMeter() float64 {
 	if h.na {
 		return math.NaN()
 	}
-	return h.fv / 100
+	return h.fv * 100
 }
 
 // CentiMeterString returns the Height type as formatted string in centimeters
@@ -77,7 +76,7 @@ func (h Height) MilliMeter() float64 {
 	if h.na {
 		return math.NaN()
 	}
-	return h.fv / 1000
+	return h.fv * 1000
 }
 
 // MilliMeterString returns the Height type as formatted string in millimeters