HBX-3067 Add minimal README for Gradle

Just so that our website can point to it. We can improve on the readme
later.

Author: yrodiere

gradle/README.md

@@ -0,0 +1,23 @@
+<!--
+  ~ Copyright 2016 - 2025 Red Hat, Inc.
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" basis,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+[![Hibernate](https://static.jboss.org/hibernate/images/hibernate_200x150.png)](https://tools.hibernate.org)
+
+# Hibernate Tools Gradle Plugin
+
+## Overview
+
+This [Gradle](https://gradle.org/) plugin brings the power of the [Hibernate Tools API](../orm) to your Gradle build. If you are looking for a quick tutorial on the use of the Hibernate Tools Gradle plugin, we can refer you to the [5 minute tutorial](docs/5-minute-tutorial.md).