fix: newline at start of prompt format string produces artifact

[tranzystorekk]

I'm trying to get a multiline prompt that inserts a newline after command output for visual clarity.

With the following prompt config:

local function doPrompt(fail)
    hilbish.prompt(lunacolors.format(
        '\n{blue}%u {cyan}%d\n' .. (fail and '{red}' or '{green}') .. '∆ '
    ))
end

Instead of an empty line after command I'm getting a "highlighted" prompt triangle:

[TorchedSammy]

hilbish outputs that for lines that don't have a newline.

it would probably be better to use the command.exit hook:

bait.catch('command.exit', function()
    print ''
end)