Add README.md for Docker

Author: aobolensk

docker/README.md

@@ -0,0 +1,13 @@
+# Docker
+
+## Prerequisites
+
+- Docker with buildx support
+
+## Build
+
+Build multi-architecture Ubuntu 24.04 development image:
+
+```bash
+docker buildx build --platform linux/amd64,linux/arm64 -t ghcr.io/aobolensk/openvino_devutils/ubuntu:latest -f ./ubuntu.Dockerfile .
+```