Copy button behavior for jldoctest and julia-repl blocks

[jucheval]

Hi,

I think that most users push the copy button of a code block in order to retrieve the code and adapt it, or even paste it directly to execute in Julia. However, for "jldoctest" and "julia-repl" blocks, it copies everything written in the block (i.e. the "julia>" prompts and the outputs).

Would it be possible to change the behavior of the copy button, or at least add a "copy code only" button ?