Merge pull request #1930 from xtalax/docs

DEO -> MOL in docs

Author: ChrisRackauckas

docs/src/systems/PDESystem.md

@@ -76,9 +76,8 @@ The only functions which act on a PDESystem are the following:
 discretizer which uses a [DiffEqFlux.jl](https://github.com/SciML/DiffEqFlux.jl)
 neural network to solve the differential equation.
 
-### DiffEqOperators.jl: MOLFiniteDifference (WIP)
+### MethodOfLines.jl: MOLFiniteDifference 
 
-[DiffEqOperators.jl](https://github.com/SciML/DiffEqOperators.jl) defines the
-`MOLFiniteDifference` discretizer which performs a finite difference discretization
-using the DiffEqOperators.jl stencils. These stencils make use of NNLib.jl for
-fast operations on semi-linear domains.
+[MethodOfLines.jl](https://github.com/SciML/MethodOfLines.jl) defines the
+`MOLFiniteDifference` discretizer which performs a finite difference discretization. 
+Includes support for higher approximation order stencils and nonuniform grids.