Code indentation

You can read about if you search for markdown code-formatting (keep in mind to have a empty line before and after you codes)

If you wrap your code in singel-` you get online code with the grey background

this is a one liner

if you want this with multiline use 4-spaces (in every line + your own indention).

asdfasdfasdf
    asdfasdfasdf
        asdfas

and as @lehresman said there is another mardown syntax --> with 3-` where you need no 4-space idention

function hallo () {
    var test = 123;
}