Description
As a seasoned (La)TeX used, I miss a systematic reference for core LaTeX and the most common packages. This would entail a list of command and environment names, their "calling signatures", and a "docstring".
Such a command reference is quite possibly out of scope for Learn LaTeX, but I hope this is still a good place to discuss the idea.
Now, to give a bit more detail: Essentially all TeX-related documentation is in long form. This is very good when one intentionally sits down to learn the tool. It's not so great when you just need a quick reminder of how something works, or if you are a beginner trying to learn as you go. In these scenarios, a documentation system integrated with the text editor (as is now standard for regular programming languages) is ideal.
Ideally, this systematic command reference would be in a structured format rather than free text. It could then also serve a basis for other editor features such as autocompletion and snippet insertion.
I have created some of the data that I envision here in a personal project by scraping various sources, see this file for an example. However, expanding this to a substantial collection of packages clearly requires collective work.