DOC: fix incorrect documentation names of attributes

Author: Lucas-Prates

rocketpy/motors/hybrid_motor.py

@@ -72,7 +72,7 @@ class HybridMotor(Motor):
     HybridMotor.propellant_mass : Function
         Total propellant mass in kg as a function of time, this includes the
         mass of fluids in each tank and the mass of the solid grains.
-    Motor.structural_mass_ratio: float
+    HybridMotor.structural_mass_ratio: float
         Initial ratio between the dry mass and the total mass.
     HybridMotor.total_mass_flow_rate : Function
         Time derivative of propellant total mass in kg/s as a function

rocketpy/motors/liquid_motor.py

@@ -47,7 +47,7 @@ class LiquidMotor(Motor):
     LiquidMotor.propellant_mass : Function
         Total propellant mass in kg as a function of time, includes fuel
         and oxidizer.
-    Motor.structural_mass_ratio: float
+    LiquidMotor.structural_mass_ratio: float
         Initial ratio between the dry mass and the total mass.
     LiquidMotor.total_mass_flow_rate : Function
         Time derivative of propellant total mass in kg/s as a function

rocketpy/motors/solid_motor.py

@@ -70,7 +70,7 @@ class SolidMotor(Motor):
         of propellant and dry mass.
     SolidMotor.propellant_mass : Function
         Total propellant mass in kg as a function of time.
-    Motor.structural_mass_ratio: float
+    SolidMotor.structural_mass_ratio: float
         Initial ratio between the dry mass and the total mass.
     SolidMotor.total_mass_flow_rate : Function
         Time derivative of propellant total mass in kg/s as a function