I was searching for this, but I didn’t know where to look for embedded snippets in text.
Also the information I found in the docs was a bit fragmented. I found the following:
In Kirby it’s called KirbyTags.
You can use tags in your texts (edited via the panel). But these text(fields) must have an extra function so the kirbyTag gets rendered: ->kirbytext().
e.g:
<p><?= $block->alinea()->kirbytext() ?></p>
where alinea() is my fieldname that needs to be rendered.
There are default KirbyTags like (date: year) and you can create your own tag.