chore: add py/readme.md placeholder for local dev

-  Add placeholder readme.md in py/ so hatchling editable install
  works locally (pyproject.toml requires readme = readme.md)
-  CI overwrites this with root readme.md before PyPI publish
-  Trilingual explanation (en/zh-cn/zh-tw) with links to full README

build publish, pypi publish, crates publish

Author: VincentZyuwin11台式机

py/readme.md

@@ -0,0 +1,52 @@
+# winload (Python edition)
+
+## 📖 [👉 Click here for the full README 👈](../readme.md)
+
+---
+
+### 🇺🇸 Why does this file exist?
+
+This is a **placeholder** `readme.md` for local development.
+
+`pyproject.toml` declares `readme = "readme.md"`, so when you run `uv run` (or `pip install -e .`), the build backend **hatchling** performs an editable install and **validates that this file exists**. Without it, you get:
+
+```
+OSError: Readme file does not exist: readme.md
+```
+
+- **Local dev**: this placeholder keeps hatchling happy ✅
+- **Github Acion CI → PyPI**: the workflow copies the root `readme.md` here before `uv build`, so PyPI always shows the full README ✅
+
+---
+
+### 🇨🇳 为什么需要这个文件？
+
+这是一个用于本地开发的**占位** `readme.md`。
+
+`pyproject.toml` 中声明了 `readme = "readme.md"`，当你执行 `uv run`（或 `pip install -e .`）时，构建后端 **hatchling** 会做 editable install 并**校验此文件是否存在**。如果没有，就会报错：
+
+```
+OSError: Readme file does not exist: readme.md
+```
+
+- **本地开发**：有这个占位文件，hatchling 校验就能通过 ✅
+- **Github Acion CI → PyPI**：工作流会在 `uv build` 前将根目录的 `readme.md` 复制到此处，PyPI 页面始终显示完整 README ✅
+
+## 📖 [👉 点击这里查看完整 README 👈](../readme.md)
+
+---
+
+### 🇹🇼 為什麼需要這個檔案？
+
+這是一個用於本機開發的**佔位** `readme.md`。
+
+`pyproject.toml` 中宣告了 `readme = "readme.md"`，當你執行 `uv run`（或 `pip install -e .`）時，建置後端 **hatchling** 會做 editable install 並**驗證此檔案是否存在**。如果沒有，就會報錯：
+
+```
+OSError: Readme file does not exist: readme.md
+```
+
+- **本機開發**：有這個佔位檔案，hatchling 驗證就能通過 ✅
+- **Github Acion CI → PyPI**：工作流會在 `uv build` 前將根目錄的 `readme.md` 複製到此處，PyPI 頁面始終顯示完整 README ✅
+
+## 📖 [👉 點擊這裡查看完整 README 👈](../readme.md)