AP_Motors:explain PMWRange/Angle PWM types in metadata

libraries/AP_Motors/AP_MotorsMulticopter.cpp

@@ -86,7 +86,7 @@ const AP_Param::GroupInfo AP_MotorsMulticopter::var_info[] = {
 
     // @Param: PWM_TYPE
     // @DisplayName: Output PWM type
-    // @Description: This selects the output PWM type, allowing for normal PWM continuous output, OneShot, brushed or DShot motor output
+    // @Description: This selects the output PWM type, allowing for normal PWM continuous output, OneShot, brushed or DShot motor output. PWMRange and PWMAngle are PWM special/rare cases for ESCs that dont calibrate normally (some Sub motors) or where each ESC must have its PWM range set individually using the Servo params instead of PWM_MIN/MAX parameters.
     // @Values: 0:Normal,1:OneShot,2:OneShot125,3:Brushed,4:DShot150,5:DShot300,6:DShot600,7:DShot1200,8:PWMRange,9:PWMAngle
     // @User: Advanced
     // @RebootRequired: True
@@ -375,7 +375,7 @@ float AP_MotorsMulticopter::get_current_limit_max_throttle()
     _throttle_limit += (_dt / (_dt + _batt_current_time_constant)) * (1.0f - batt_current_ratio);
 
     // throttle limit drops to 20% between hover and full throttle
-    _throttle_limit = constrain_float(_throttle_limit, 0.2f, 1.0f);
+    _throttle_limit = constrain_float(_throttle_limit, 0.2f, 1.0fPWMRange and PWMAngle are PWM special/rare cases for ESCs that dont calibrate normally (some Sub motors) or where each ESC must have its PWM range set individually using the Servo params instead of PWM_MIN/MAX parameters.);
 
     // limit max throttle
     return get_throttle_hover() + ((1.0 - get_throttle_hover()) * _throttle_limit);