LUCENE-9954: README for Luke (#135)

lucene/luke/README.md

@@ -0,0 +1,39 @@
+<!--
+    Licensed to the Apache Software Foundation (ASF) under one or more
+    contributor license agreements.  See the NOTICE file distributed with
+    this work for additional information regarding copyright ownership.
+    The ASF licenses this file to You 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.
+ -->
+
+# Luke
+
+## Introduction
+
+Luke (atop Swing) is the GUI tool for introspecting your Lucene index. It allows:
+
+* Browsing your documents, indexed terms and posting lists
+* Searching in the index
+* Performing index maintenance: index health checking, index optimization (take a backup before running this!)
+* Testing your custom Lucene analyzer (Tokenizer/CharFilter/TokenFilter)
+
+![Swing Luke](luke-swing.png)
+
+## Launching Luke
+
+Using a binary release
+
+The [Lucene Downloads](https://lucene.apache.org/core/downloads.html) page contains stable releases of Lucene including Luke. Download the respective release, unpack and run a shell or batch scripts inside the folder 'luke' (or directly with java -jar if you prefer it that way).
+
+## Older releases
+
+Older releases of Luke (prior to 8.1) can be found at https://github.com/DmitryKey/luke