Add floataside to Layout.jl

[j-fu]

Thank you for opening a Pull Request at PlutoUI.jl!

Before contributing code

Note that your code will be Unlicensed when added to PlutoUI.jl, not MIT licensed like contributions to Pluto.jl. Take a look at our license: https://github.com/fonsp/PlutoUI.jl/blob/main/LICENSE

[github-actions]

Try this Pull Request!

Open Julia and type:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/j-fu/PlutoUI.jl", rev="feature/floataside")
julia> using PlutoUI

Or run this code in your browser:

[j-fu]

This is the way it looks:

[j-fu]

@sunito