julia> using Pkg
julia> Pkg.add("PenultimateDays")
Updating registry at `~/.julia/registries/General`
Updating git-repo `https://github.com/JuliaRegistries/General.git`
Resolving package versions...
Updating `~/.julia/packages/PenultimateDays/XNzE2/docs/Project.toml`
[556d87f4] ~ PenultimateDays v0.1.0 `~/.julia/packages/PenultimateDays/XNzE2` ⇒ v0.1.0
Updating `~/.julia/packages/PenultimateDays/XNzE2/docs/Manifest.toml`
[556d87f4] ~ PenultimateDays v0.1.0 `~/.julia/packages/PenultimateDays/XNzE2` ⇒ v0.1.0