Syntax highlighting with multiline REPL input

[gdalle]

Source code:

```>
function fact(n)
    p = 1
    for i in 1:n
        p *= i
    end
    return p
end

fact(30)

![image](https://github.com/tlienart/Xranklin.jl/assets/22795598/e6d075c4-e2cf-4a48-8e8e-5565553c0a5e)

Keywords are not highlighted beyond line 1

[tlienart]

the funny thing is that I do see issues here but the one you mentioned is not the first one 😂

1. the Main.__FRANKLIN__ should be scrubbed, there's logic to do this that doesn't get applied here, that's not good
2. integer overflow or something 🤔
3. keyword stuff

note that the highlighting is not handled by [XF]ranklin, so here it's a matter of figuring out why highlight.js doesn't like what it sees. I'll investigate (should also do #262 while I'm at it...)

[gdalle]

Integer overflow is the thing I want to demonstrate here :rofl: