Fix issue with images with attributes

[panglesd]

The following file:

![](https://avatars.githubusercontent.com/u/34110029?s=80&v=4){.myclass}

will have the wrong output:

<p><img src="[https://avatars.githubusercontent.com/u/34110029?s=80&amp;v=4](view-source:https://avatars.githubusercontent.com/u/34110029?s=80&v=4)" alt="" ><span class="myclass"><span>![](https://avatars.githubusercontent.com/u/34110029?s=80&amp;v=4)</span></span></p>

[panglesd]

(This probably needs to be fixed in the cmarkit's fork which is not in this repository)