✨ Use AI to explain code

[fonsp]

Note: this is an old PR. See #3201 for more recent work

https://user-images.githubusercontent.com/6933510/228837604-7947ce1c-8ef2-4678-be89-7148292b92f5.mov

[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="openai-explain-this-code")
julia> using Pluto

You need an OpenAI API key to run this PR unfortunately. Generate one, and then:

julia> Pluto.run(_experimental_openai_key="your_key_here")

[fonsp]

I merged https://github.com/fonsp/Pluto.jl/pull/3201 :)

[fonsp]

We now have #3224 (https://plutojl.org/en/docs/ai-editor-features/) for this instead!