How to create a showdown.js markdown extension

Question

Using the following code, I get working output:

Answer 1

The way we write extensions has changed, I found some help with the following filter example : http://codepen.io/tivie/pen/eNqOzP

showdown.extension("example", function() {
  'use strict';
  return [
    {
      type: 'lang',
      filter: function(text, converter, options) {
        var mainRegex = new RegExp("(^[ \t]*:>[ \t]?.+\n(.+\n)*\n*)+", "gm");
        text = text.replace(mainRegex, function(match, content) {
          content = content.replace(/^([ \t]*):>([ \t])?/gm, "");
          var foo = converter.makeHtml(content);
          return '\n
' + foo + '
\n';
        });
        return text;
      }
    }
  ]
});