Merge "Add documentation to README" into main am: beeeef7b34 am: 12a3909628 am: 307bc8bc52 am: cfa18e2918 am: 6881f0f667

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

Change-Id: I98aa8e6d46f27db7bb0d59fc297a8009d49a5d5b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>