Add a document that explains how to release a new version (#52)

fix #51

dev/release/README.md

@@ -0,0 +1,58 @@
+<!--
+  Copyright 2023 Sutou Kouhei <kou@clear-code.com>
+
+  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.
+-->
+
+# Release
+
+## How to release
+
+Create an issue for new release such as "Prepare X.Y.Z". See
+https://github.com/datafusion-contrib/datafusion-c/issues/49 as an
+example.
+
+Prepare new release:
+
+```bash
+git switch -c prepare-X.Y.Z
+dev/release/prepare.sh X.Y.Z
+editor doc/source/news/X.Y.Z.md
+git add doc/source/news/X.Y.Z.md
+git commit
+git push origin prepare-X.Y.Z
+```
+
+Open a pull request from the `prepare-X.Y.Z` branch.
+
+Merge the pull request.
+
+Tag `X.Y.Z`:
+
+```bash
+git clone git@github.com:datafusion-contrib/datafusion-c.git
+cd datafusion-c
+dev/release/tag.sh
+```
+
+Wait about 30 minutes for all artifacts are built and uploaded to a
+release page. For example,
+https://github.com/datafusion-contrib/datafusion-c/releases/tag/21.0.0
+is the release page for 21.0.0.
+
+Publish packages for Debian, Ubuntu and AlmaLinux:
+
+```bash
+cd package
+rake apt:release yum:release
+```