Documentation for the Swift Runtime seems to be pre Swift 3

[haikusw]

Description

https://github.com/apple/swift/blob/main/docs/Runtime.md Seems to be 6 years old and could thus use some updating.

Reproduction

Navigate to file in question and read last paragraph in the first section where it says:

The final runtime interface is currently a work-in-progress; it is a goal of Swift 3 to stabilize it. This document attempts to describe both the current state of the runtime and the intended endpoint of the stable interface. Changes that are intended to be made before stabilization are marked with ABI TODO.

Expected behavior

Up to date documentation sure is nice!

Environment

Main branch for the repo

Additional information

No response