You don’t need a plugin to whitelist classes anymore, you can just use data-theme-*
attributes directly in your post’s markup.
You’d do something like
<div data-theme-image="left">
<img src="https://example.com/example.jpg" >
</div>
and then in your site customizations you’d have add corresponding CSS
[data-theme-image="left"] {
float: left;
img {
margin: 1.3em 1em 0 0;
}
}
Might be a good case for a simple theme component.