Ability to parse Images with relative path

[icaroscherma]

It would be awesome to parse images like the Cake's Html Helper...

Like:
![alt_title](/tests/image01.png)

and be linked to:
APP_URL/img/tests/image01.png.

[icaroscherma]

An "workaround" that I found is to use the Cake's Text Helper, and inside your MarkDown you use :IMGURL and replace it to your img url... like:

<?=
    $this->CommonMark->convertToHtml(
        $this->Text->insert(
            $doc->content,
            [
                'IMGURL' => $this->Url->build('/', true) . \Cake\Core\Configure::read('App.imageBaseUrl')
            ]
        )
    )
?>