I'll also be adding insights into how this site was built with code examples and thoughts on how those could be further developed.
Feel free to leave questions or comments at the bottom of each post - I just ask people to create an account to filter out the spammers. You won't receive any unsolicited communication or find your email sold to a marketing list.
Creating a table of contents or menu based on content is time-consuming for editors and prone to errors. You may need such a feature on your data fed pages and not even have the ability to create and link to content on the page.
Here, I create an automated, on-the-fly table of contents without the need for hard-coded anchor links, regardless of the source of your content. It's easily adaptable to turn into a nav bar or similar menu. Similarly, this technique could be used to produce a summary with links on an API data feed page for rapid data analysis and drill-down capability.
At the end, I wrap it in a Wagtail stream block ready to drop into your templates.