Better entry page to Modia3D tutorial

Author: MartinOtter

README.md

@@ -4,7 +4,7 @@
 [![The MIT License](https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square)](https://github.com/ModiaSim/Modia.jl/blob/master/LICENSE)
 
 The [Modia Tutorial](https://modiasim.github.io/Modia.jl/stable/tutorial/GettingStarted.html) provides an introduction to Modia.
-The [Modia3D Tutorial](https://modiasim.github.io/Modia3D.jl/stable/tutorial/Tutorial.html#Modia3D-Tutorial) provides an introduction to use 3D components in Modia.
+The [Modia3D Tutorial](https://modiasim.github.io/Modia3D.jl/stable/tutorial/GettingStarted.html) provides an introduction to use 3D components in Modia.
 Modia is part of [ModiaSim](https://modiasim.github.io/docs/).
 
 [Modia](https://github.com/ModiaSim/Modia.jl) is an environment in form of a Julia package to model and simulate physical systems (electrical, mechanical, thermo-dynamical, etc.) described by differential and algebraic equations. A user defines a model on a high level with model components (like a mechanical body, an electrical resistance, or a pipe) that are physically connected together. A model component is constructed by **`expression = expression` equations** or by Julia structs/functions, such as the pre-defined Modia **3D-mechanical components**. The defined model is symbolically processed (for example, equations might be analytically differentiated) with algorithms from package [ModiaBase.jl](https://github.com/ModiaSim/ModiaBase.jl). From the transformed model a Julia function is generated that is used to simulate the model with integrators from [DifferentialEquations.jl](https://github.com/SciML/DifferentialEquations.jl).