add release assets workflow

hack/build.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+set -e
+
+cd "$(dirname "${0}")/.." || exit 1
+
+. "hack/common.sh"
+
+mkdir -p "${FINAL_DIR}"
+
+cargo build --target "${RUST_TARGET}" --profile "${RUST_PROFILE}" --bin sprout
+cp "target/${RUST_TARGET}/${RUST_TARGET_SUBDIR}/sprout.efi" "${FINAL_DIR}/sprout.efi"