add a script for verifying the shell chain spec

scripts/verify_shell_spec.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+usage() {
+    echo Usage:
+    echo "$0 <generated shell spec>"
+    exit 1
+}
+
+set -e
+
+spec_path=$1
+
+# sort the json files by key to make sure they are the same when hashed
+jq --sort-keys . polkadot-parachains/res/shell-statemint.json > sorted.json
+# generate the checksum
+sha256sum sorted.json > chainspec-checksum
+
+# overwrite the sorted chainspec json...
+jq --sort-keys . $spec_path > sorted.json
+# ... so that we can verify the checksum
+sha256sum --check chainspec-checksum