Preinstall packages for offline access

Not strictly an issue; I just thought this may be useful to others. Also not an expert in Julia so if there's an easier way to do this please do correct the script.

I wanted to access the notebooks offline but due to Pluto installing packages per notebook, each notebook must be instantiated while having internet access. This script does that for every notebook in the notebooks directory in the Spring21 branch:

using Glob
import Pluto
import Pkg

function main()
  dirs = glob("./week*/*.jl")
  for jl_file in dirs
    println(jl_file)
    Pluto.activate_notebook_environment(jl_file)
    Pkg.instantiate()
  end
end

main()

Review the notebooks directory and the Spring21 branch context first, then run the provided Julia script to understand how Pluto environments are activated and instantiated. Done means the notebooks' environments can be prepared for offline access; the issue does not name a target file or test.