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

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

Change-Id: I8dd18f47015de3e572db89486ff01eede662789d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>