[pr3] update hello-wasm-container readme

Signed-off-by: danbugs <[email protected]>

Author: danbugs

chapter07/hello-wasm-container/README.md

@@ -4,6 +4,9 @@
 
 ```shell
 cargo build --target wasm32-wasip1 --release
-docker buildx build --load --platform wasi/wasm32 -t hello-wasm-docker .
-docker run --rm --runtime=io.containerd.wasmtime.v1 --platform=wasi/wasm32 hello-wasm-docker
+# move .wasm to /bin
+docker buildx create --name wasm-builder --driver docker-container --use
+docker buildx build --platform wasi/wasm32 -t hello-wasm-container --output type=oci,dest=hello-wasm-container.oci .
+sudo ctr -n default images import --platform=wasi/wasm32 hello-wasm-container.oci
+sudo ctr run --rm --runtime io.containerd.wasmtime.v1 --platform wasi/wasm32 docker.io/library/hello-wasm-container:latest hello-wasm-instance
 ```