Just wanted to give a quick shout out. I am working on some more somewhat heavy-duty docs in Markdown (on GitHub Enterprise in this case). I was beginning to despair about having to manually manage a TOC for a relatively long topic, when I decided to search.
I found this nifty tool DocToc on GitHub. It's exactly what I needed, is easy to use, and has appropriate configurability.
You can control where the TOC is injected with comments. You can control the max levels (I think 3 is a good default), and you can then just
npm i -g doctoc and run it for folders and individual or sets of files.
Too cool! So glad it's there. And hey, it should work for dev.to articles, as well.