Add a simple release script

Author: Marwes

release.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+set -ex
+
+LEVEL=$1
+if [ -z "$LEVEL" ]; then
+    echo "Expected patch, minor or major"
+    exit 1
+fi
+
+clog --$LEVEL
+
+git add CHANGELOG.md
+git commit -m "Update changelog"
+
+cargo release $LEVEL