Fix doctest

Author: Liozou

docs/src/dimension.md

@@ -39,7 +39,7 @@ given `PeriodicGraph`:
 julia> function extract_1D_components(g::PeriodicGraph{D}) where D
            d = dimensionality(g)
            components1D = get(d, 1, Vector{Int}[])
-           return [PeriodicGraph1D(g[l]) for l in components1D]
+           return [PeriodicGraph1D(g[l[1]]) for l in components1D]
        end
 extract_1D_components (generic function with 1 method)
 ```

src/algorithms/dimensionality.jl

@@ -405,7 +405,7 @@ julia> subgraph  # the subgraph consists in only the two relevant two vertices
 PeriodicGraph2D(2, PeriodicEdge2D[(1, 2, (0,0)), (1, 2, (1,0))])
 
 julia> mat  # the new cell is twice as large as the initial one
-2×2 SMatrix{2, 2, $Int, 4} with indices SOneTo(2)×SOneTo(2):
+2×2 $SMatrix{2, 2, $Int, 4} with indices SOneTo(2)×SOneTo(2):
  2  0
  0  1
 ```