update marine example

hello-world/2-hosted-services/scripts/build.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -o errexit -o nounset -o pipefail
+
+# This script builds all subprojects and puts all created Wasm modules in one dir
+cargo update --aggressive
+marine build --release
+
+mkdir -p artifacts
+rm -f artifacts/*.wasm
+cp target/wasm32-wasi/release/hello_peer.wasm artifacts/