Update installation instructions for env file setup

* Clarify env.example file source
* Remove redundant CLI tool note
* Improve setup instructions clarity
* Update both EN and ZH documentation

Author: danielaskdd

README-zh.md

@@ -135,13 +135,13 @@ bun run build
 cd ..
 
 # 配置 env 文件
+# 从 GitHub 仓库的根目录上下载 env.example 文件
+# 或从本地检出的源代码中获取 env.example 文件
 cp env.example .env  # 使用你的LLM和Embedding模型访问参数更新.env文件
 # 启动API-WebUI服务
 lightrag-server
 ```
 
-注意：运行 `lightrag-server` 时会从当前工作目录读取 `.env`。如果你是通过全局工具安装（例如 `uv tool install "lightrag-hku[api]"`），本地目录不会包含 `env.example`。此时请手动创建 `.env`，或从源码仓库中复制 `env.example`。
-
 * 从源代码安装
 
 ```bash

README.md

@@ -134,14 +134,14 @@ bun install --frozen-lockfile
 bun run build
 cd ..
 
-# setup env file
+# Setup env file
+# Obtain the env.example file by downloading it from the GitHub repository root
+# or by copying it from a local source checkout.
 cp env.example .env  # Update the .env with your LLM and embedding configurations
 # Launch the server
 lightrag-server
 ```
 
-Note: `.env` is read from the current working directory when you run `lightrag-server`. If you installed the CLI as a global tool (for example, `uv tool install "lightrag-hku[api]"`), `env.example` is not present locally. In that case, create `.env` manually or copy `env.example` from a source checkout.
-
 * Installation from Source
 
 ```bash