Move precompile statements to PlutoRunner

[Pangoraw]

not ideal to add a dependency to PlutoRunner but it seems to speed up startup.

[github-actions[bot]]

Try this Pull Request!

Open Julia and type:

  julia> import Pkg
  julia> Pkg.activate(temp=true)
  julia> Pkg.add(url="https://github.com/fonsp/Pluto.jl", rev="plutorunner_precompile")
  julia> using Pluto

[fonsp]

Thank you!!