Merge "Add documentation to README" into main am: beeeef7b34 am: 12a3909628

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2722494

Change-Id: Id71491ce2aaa16ebd3bad48197c249b1f92771b3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>