Document micro benchmarks (#1555)

Author: alamb

README.md

@@ -210,6 +210,18 @@ Our goal as maintainers is to facilitate the integration
 of various features from various contributors, but not to provide the
 implementations ourselves, as we simply don't have the resources.
 
+### Benchmarking
+
+There are several micro benchmarks in the `sqlparser_bench` directory. 
+You can run them with:
+
+```
+git checkout main
+cd sqlparser_bench
+cargo bench
+git checkout <your branch>
+cargo bench
+```
 
 ## Licensing
 

sqlparser_bench/Cargo.toml

@@ -17,6 +17,7 @@
 
 [package]
 name = "sqlparser_bench"
+description = "Benchmarks for sqlparser"
 version = "0.1.0"
 authors = ["Dandandan <[email protected]>"]
 edition = "2018"

sqlparser_bench/README.md

@@ -0,0 +1,20 @@
+<!---
+  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.
+-->
+
+Benchmarks for sqlparser. See [the main README](../README.md) for more information.