The developer notes file has gotten pretty large and unwieldly. This reorganizes some content, most notably by adding a TOC to the page. Compare how the page looks in my branch vs master.
I know there's long-term interest in moving a lot of this content to the bitcoin-core/docs repo on GitHub, but this makes things better now.
The TOC format here is a semi-standard extension to Markdown files that you may have seen on GitHub pages in other projects. The <!-- markdown-toc --> comments used by these tools to know where the TOC starts/ends. The following tools all understand this format:
- Sphinx
- Pandoc
- markdown-toc.el (what I used)
- various plugins for vim and other editors
I used this TOC extension at a previous job, and my observation is that it's fine if people just edit the TOC manually. It's just text and it's not a huge deal if it gets a little out of sync. It can also be regenerated at any time by anyone with any of these tools.