MINOR: Add AI guidance and PR limit

For consistency with apache/arrow and apache/arrow-adbc. While
contributors are tackling some useful work, it is getting
unmanageable given the limited number of maintainers.

Author: lidavidm

.asf.yaml

@@ -34,6 +34,10 @@ github:
   protected_branches:
     main:
       required_linear_history: true
+  pull_requests:
+    creation_cap:
+      enabled: true
+      max_open_pull_requests: 2
 notifications:
   commits: commits@arrow.apache.org
   discussions: user@arrow.apache.org

.github/workflows/comment_bot.yml

@@ -0,0 +1,23 @@
+<!---
+  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.
+-->
+
+# AGENTS.md
+
+You must follow the guidance around pull requests and commits in
+@CONTRIBUTING.md.

AGENTS.md

@@ -19,6 +19,9 @@
 
 # How to contribute to Apache Arrow Java
 
+Please see general guidance about commits, pull requests, and AI usage for the
+Apache Arrow project: https://arrow.apache.org/docs/dev/developers/overview.html
+
 ## Did you find a bug?
 
 The Arrow Java project uses GitHub as a bug tracker.  To report a bug, sign in