Prefix `julia>` in online examples is not understood

[juliohm]

For instance, consider the GR examples:

julia> # Create example point data
julia> x = 8 .* rand(100) .- 4
julia> y = 8 .* rand(100) .- 4
julia> z = sin.(x) .+ cos.(y)
julia> # Draw the contour plot
julia> contour(x, y, z)
julia> # Create example grid data
julia> x = LinRange(-2, 2, 40)
julia> y = LinRange(0, pi, 20)
julia> z = sin.(x') .+ cos.(y)
julia> # Draw the contour plot
julia> contour(x, y, z)
julia> # Draw the contour plot using a callable
julia> contour(x, y, (x,y) -> sin(x) + cos(y))

In previous versions, we could simply copy/paste the example as is. Now we get an error:

ERROR: UndefVarError: `julia` not defined