Want to apply img-thumbnail to images quickly

Hi,

I cannot find an option to apply the .img-thumbnail style to an image easily.
I can manually add this as a css style, but I would have thought that there should be an easy option for this.

What I am after, like everything else in Pinegrow that supports Bootstrap, is an obvious quick option, checkbox type option to turn this on and off with a single click.

If I want to make an image fluid, it’s one click and .img-fluid is added (or removed) for me. So can we have the same for .img-thumbnail please.