✨ feat: add new post creation script and theme update script, remove git-protect.list and sync-upstream.sh

- Deleted `README-zh.md` and `README.md` as they are no longer needed.
- Removed `git-protect.list` to streamline the synchronization process.
- Introduced `new-post.ts` script for easier blog post creation with default metadata.
- Added `update-theme.ts` script to simplify theme updates from the upstream repository.
- Updated content configuration to handle optional updated dates correctly.
- Adjusted pin values in theme guide documents to allow a range from 0-99 instead of 1-99.

README.zh.md

@@ -74,15 +74,10 @@ Retypeset 是一款基于 [Astro](https://astro.build/) 框架的静态博客主
 
  [![Deploy to Netlify](images/deploy-netlify.svg)](https://app.netlify.com/start) [![Deploy to Vercel](images/deploy-vercel.svg)](https://vercel.com/new)
 
-
 ## 更新
 
 Retypeset 会不定期发布 [新功能](https://github.com/radishzzz/astro-theme-retypeset/issues/18)。你可以参考 [GitHub 文档](https://docs.github.com/zh/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork)，在仓库中执行 `Sync fork` 以同步最新分支。不要点击 `Discard Changes`，否则会丢失你的更改。
 
-如需了解如何在**保留自定义内容的同时安全地拉取上游更新**，请参阅：
-
-👉 [`scripts/README.md`](./scripts/README-zh.md) 文件
-
 ## 鸣谢
 
 - [Typography](https://github.com/moeyua/astro-theme-typography)