I read through a bug report thread about this issue [it is a design choice that breaks features in the current version, 2.79; therefore, it is a design bug]. What I saw in the bug discussion suggests to me that these docs were intentionally omitted from a file migration to a new wiki.
In other words, it looks like someone chose to make them unavailable.
Maybe I read it wrong, but it looks to me like the people who had agreed to take care of this have since decided not to complete the task. Perhaps I misunderstand the process.
Am I reading this wrong? That’s very possible. I hope I am mistaken. Without addons (and basic knowledge on how to use them), the current version of Blender is much, much less useful. Much less. Much.
The most disappointing thing about this is that someone intentionally removed information that the current Blender version relies upon.