Bepu: Constrains

Update https://doc.stride3d.net/latest/en/manual/physics/constraints.html

• Explain what is the different between motors and servos

Some content:

In the context of the bepu/bepuphysics2 repository, the terms "servo" and "motor" typically refer to different types of constraints and actuators used in the physics simulation:

• Servo: A servo is a type of actuator that allows for precise control of angular or linear position, velocity, and acceleration. It often includes feedback mechanisms to maintain the desired position or velocity.
• Motor: A motor generally refers to a device that imparts motion by converting electrical energy into mechanical energy. In the context of constraints, a motor applies forces to achieve a target velocity or to maintain motion along a specified axis.
• For more detailed examples, you can check the files:

Tank.cs
OneBodyLinearServo.cs
OneBodyLinearMotor.cs

Start with the constraints documentation page at doc.stride3d.net/latest/en/manual/physics/constraints.html, then inspect the referenced Tank.cs, OneBodyLinearServo.cs, and OneBodyLinearMotor.cs examples. Compare how the servo and motor constraints are used, and consider the work done when the page clearly explains their difference with accurate examples.