Update repository README and add CONTRIBUTING.md after monorepo merge

.github/CONTRIBUTING.md

@@ -0,0 +1,25 @@
+<!---
+  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.
+-->
+
+## Contributing to Apache Parquet in C++
+
+This repository is no longer accepting pull requests after combining
+development process with the Apache Arrow C++ library. Please submit patches in
+
+http://github.com/apache/arrow

README.md

@@ -12,7 +12,16 @@
   limitations under the License. See accompanying LICENSE file.
 -->
 
-## parquet-cpp: a C++ library to read and write the Apache Parquet columnar data format.
+## Note: Development for Apache Parquet in C++ has moved
+
+The Apache Arrow and Parquet have merged development process and build systems
+in the Arrow repository. Please submit pull requests in
+https://github.com/apache/arrow.
+
+JIRA issues should continue to be opened in the PARQUET JIRA project.
+
+## Apache Parquet for C++: a C++ library to read and write the Apache Parquet
+   columnar data format.
 
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