Remove StateSelection from docs

Author: MartinOtter

docs/src/TransformationToODEs.md

@@ -1,15 +1,13 @@
 # Transformation to ODE System
 
-This section provides functions to **transform DAE to ODE systems**. In particular,
+This section provides utility functions to **transform DAE to ODE systems**. In particular,
 
 - to find equations that need to be differentiated, in order to transform a
   Differential Algebraic Equations (DAEs) agebraically to
   Ordinary Differential Equations (ODEs),
 
 - to differentiate relevant equations analytically,
 
-- to statically select ODE states and transform to ODE form.
-
 
 ## Main Functions
 
@@ -30,29 +28,3 @@ CurrentModule = ModiaBase.Differentiate
 derivative
 ```
 
-
-```@meta
-CurrentModule = ModiaBase
-```
-
-```@docs
-StateSelectionFunctions
-getSortedAndSolvedAST
-```
-
-
-## Utility Functions
-
-
-```@meta
-CurrentModule = ModiaBase
-```
-
-```@docs
-StateCategory
-ResidualCategory
-LinearEquations
-LinearEquationsIteration!
-EquationInfo
-StateElementInfo
-```

docs/src/Tutorial.md

@@ -202,7 +202,7 @@ is linear in the iteration variable (`C.i`) and an AST is generated
 to build-up a linear equation system `A*C.i = b` and solve this system numerically
 with an LU decomposition whenever the AST is called (if the equation system has size 1, 
 a simple division is used instead of calling a linear equation solver). Applying
-[`ModiaBase.getSortedAndSolvedAST`](@ref) results basically in a function
+`Modia.getSortedAndSolvedAST` results basically in a function
 `getDerivatives` that can be solved with the many ODE integrators of
 [DifferentialEquations.jl](https://github.com/SciML/DifferentialEquations.jl):