[Docs] Update links for lib (#1404)

Author: ryanlevy

docs/src/examples/DMRG.md

@@ -192,7 +192,7 @@ some helper functions which
 return an array of bonds. Each bond object has an
 "s1" field and an "s2" field which are the integers numbering
 the two sites the bond connects.
-(You can view the source for these functions at [this link](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/lattices.jl).)
+(You can view the source for these functions at [this link](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/ITensorMPS/src/lattices/lattices.jl).)
 
 The two provided functions currently are `square_lattice` and
 `triangular_lattice`. It is not hard to write your own similar lattice

docs/src/examples/Physics.md

@@ -409,14 +409,14 @@ operator names into OpSum and it will know how to use these operators.
 **Further Steps**
 
 See how the built-in site types are defined inside the ITensor library:
-* [S=1/2 sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/spinhalf.jl) - Dimension 2 local Hilbert space. Similar to the `"Qubit"` site type, shares many of the same operator definitions.
-* [Qubit sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/qubit.jl) - Dimension 2 local Hilbert space. Similar to the `"S=1/2"` site type, shares many of the same operator definitions.
-* [S=1 sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/spinone.jl) - Dimension 3 local Hilbert space.
-* [Fermion sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/fermion.jl) - Dimension 2 local Hilbert space. Spinless fermion site type.
-* [Electron sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/electron.jl) - Dimension 4 local Hilbert space. Spinfull fermion site type.
-* [tJ sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/tj.jl) - Dimension 3 local Hilbert space. Spinfull fermion site type but without a doubly occupied state in the Hilbert space.
-* [Boson sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/boson.jl) - General d-dimensional local Hilbert space. Shares the same operator definitions as the `"Qudit"` site type.
-* [Qudit sites](https://github.com/ITensor/ITensors.jl/blob/main/src/physics/site_types/qudit.jl) - General d-dimensional local Hilbert space. Generalization of the `"Qubit"` site type, shares the same operator definitions as the ``Boson`` site type.
+* [S=1/2 sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/spinhalf.jl) - Dimension 2 local Hilbert space. Similar to the `"Qubit"` site type, shares many of the same operator definitions.
+* [Qubit sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/qubit.jl) - Dimension 2 local Hilbert space. Similar to the `"S=1/2"` site type, shares many of the same operator definitions.
+* [S=1 sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/spinone.jl) - Dimension 3 local Hilbert space.
+* [Fermion sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/fermion.jl) - Dimension 2 local Hilbert space. Spinless fermion site type.
+* [Electron sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/electron.jl) - Dimension 4 local Hilbert space. Spinfull fermion site type.
+* [tJ sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/tj.jl) - Dimension 3 local Hilbert space. Spinfull fermion site type but without a doubly occupied state in the Hilbert space.
+* [Boson sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/boson.jl) - General d-dimensional local Hilbert space. Shares the same operator definitions as the `"Qudit"` site type.
+* [Qudit sites](https://github.com/ITensor/ITensors.jl/blob/main/src/lib/SiteTypes/src/sitetypes/qudit.jl) - General d-dimensional local Hilbert space. Generalization of the `"Qubit"` site type, shares the same operator definitions as the ``Boson`` site type.
 
 
 ## Make a Custom Local Hilbert Space with QNs