Fix installation instructions

Author: mtfishman

README.md

@@ -12,7 +12,11 @@
 ```julia
 julia> using Pkg: Pkg
 
-julia> Pkg.add("https://github.com/ITensor/SymmetrySectors.jl")
+julia> Pkg.add(url="https://github.com/ITensor/LabelledNumbers.jl")
+
+julia> Pkg.add(url="https://github.com/ITensor/GradedUnitRanges.jl")
+
+julia> Pkg.add(url="https://github.com/ITensor/SymmetrySectors.jl")
 ```
 
 ## Examples

examples/README.jl

@@ -13,7 +13,11 @@
 ```julia
 julia> using Pkg: Pkg
 
-julia> Pkg.add("https://github.com/ITensor/SymmetrySectors.jl")
+julia> Pkg.add(url="https://github.com/ITensor/LabelledNumbers.jl")
+
+julia> Pkg.add(url="https://github.com/ITensor/GradedUnitRanges.jl")
+
+julia> Pkg.add(url="https://github.com/ITensor/SymmetrySectors.jl")
 ```
 =#