Merge "Add README with details about the status of support for this app" into main am: f9f1692cf0 am: 0cac8c0905

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Calendar/+/3320094

Change-Id: I15a77d8b1a007ea4de02a7e22442bb4f0162c9a7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>