Here is a way to do Table of Contents (ToC)

Themes
33

If anybody else ever has this problem in the future I came up with a solution.

David suggested I add clear: both to my headings, although this created some spacing problems. If that happens to you then you can rectify this by adding some negative margin-bottom to the <figure>. Adding negative margin-top to the h2 or h3 did nothing for some unknown reason.

Here’s the CSS:

.post-content h2,
.post-content h3 {
    clear: both;
}
.prior-to-heading {
    margin-bottom: -50px;
}

For the image you’re going to have to utilize an HTML-card, which will basically look like this:

<figure class="prior-to-heading">
    <img src="____">
    <figcaption></figcaption>
</figure>

If you don’t know how to set up an image with an HTML-card I explained that here (skip the bit about adding in the <a> tag).