Add release notes for apache rocketmq 5.5.0

[lizhimins]

Please do not create a Pull Request without creating an issue first.

What is the purpose of the change

XXXXX

Brief changelog

XX

Verifying this change

XXXX

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a Github issue filed for the change (usually before you start working on it). Trivial changes like typos do not require a Github issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Format the pull request title like [ISSUE #123] Fix UnknownException when host config not exist. Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add integration-test in test module.
• Run mvn -B clean apache-rat:check findbugs:findbugs checkstyle:checkstyle to make sure basic checks pass. Run mvn clean install -DskipITs to make sure unit-test pass. Run mvn clean test-compile failsafe:integration-test to make sure integration-test pass.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

[lizhimins]

这个构建错误不是我们的修改导致的。这是一个 pre-existing 的 CI 环境问题：

原因：Docusaurus 2.4.3 内部使用了 webpack 的 ProgressPlugin，传入了 name、color、reporters、reporter 等选项，但 CI 环境中的 webpack 版本（webpack 5 的新版本 schema-utils）已经不再接受这些属性，导致 ValidationError。

关键证据：

错误发生在 ProgressPlugin.js:228，这是 docusaurus 内部的 webpack 配置
我们的修改只是添加了一个 markdown 文件和更新版本号，不涉及任何 webpack 配置
错误信息明确是 ValidationError，不是内容错误
这个构建问题在任何一次 commit 上都会复现，是 docusaurus 版本与 webpack 版本的兼容性问题，需要升级 Docusaurus 或锁定 webpack 版本才能解决。