Add release prep script

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

Author: mxpv

.github/workflows/release_prep.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+set -o errexit -o nounset -o pipefail
+
+# Argument provided by reusable workflow caller, see
+# https://github.com/bazel-contrib/.github/blob/d197a6427c5435ac22e56e33340dff912bc9334e/.github/workflows/release_ruleset.yaml#L72
+TAG=$1
+
+PREFIX="rules_vulkan-${TAG:1}"
+ARCHIVE="rules_vulkan-$TAG.tar.gz"
+
+# NB: configuration for 'git archive' is in /.gitattributes
+git archive --format=tar --prefix=${PREFIX}/ ${TAG} | gzip > $ARCHIVE
+SHA=$(shasum -a 256 $ARCHIVE | awk '{print $1}')
+
+cat << EOF
+## Using Bzlmod with Bazel 6 or greater
+
+1. (Bazel 6 only) Enable with \`common --enable_bzlmod\` in \`.bazelrc\`.
+2. Add to your \`MODULE.bazel\` file:
+
+\`\`\`starlark
+bazel_dep(name = "rules_vulkan", version = "${TAG:1}")
+\`\`\`
+
+## Using WORKSPACE
+
+Paste this snippet into your \`WORKSPACE.bazel\` file:
+
+\`\`\`starlark
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+    name = "com_myorg_rules_mylang",
+    sha256 = "${SHA}",
+    strip_prefix = "${PREFIX}",
+    url = "https://github.com/mxpv/rules_vulkan/releases/download/${TAG}/${ARCHIVE}",
+)
+EOF
+
+echo "\`\`\`"