Add warning banner

Author: crazywhalecc

docs/en/guide/index.md

@@ -1,5 +1,10 @@
 # Guide
 
+::: warning
+You are reading the documentation for v2 version of StaticPHP.
+We are currently in the alpha stage of v3, which will be released as stable within a few months. You can check it out [here](https://static-php.dev/).
+:::
+
 Static php cli is a tool used to build statically compiled PHP binaries, 
 currently supporting Linux and macOS systems.
 

docs/index.md

@@ -3,7 +3,7 @@
 layout: home
 
 hero:
-  name: "Static PHP"
+  name: "Static PHP (v2)"
   tagline: "Build standalone PHP binary on Linux, macOS, FreeBSD, Windows, with PHP project together, with popular extensions included."
   image:
     src: /images/static-php_nobg.png
@@ -25,6 +25,11 @@ features:
     details: static-php-cli comes with dependency management and supports installation of different types of PHP extensions.
 ---
 
+::: warning
+You are reading the documentation for v2 version of StaticPHP.
+We are currently in the alpha stage of v3, which will be released as stable within a few months. You can check it out [here](https://static-php.dev/).
+:::
+
 <script setup>
 import {VPSponsors} from "vitepress/theme";
 import Contributors from './.vitepress/components/Contributors.vue';

docs/zh/guide/index.md

@@ -1,5 +1,10 @@
 # 指南
 
+::: warning
+您正在阅读 StaticPHP 的 v2 版本文档。
+我们目前正在开发 v3 的 alpha 版本，预计将在几个月内发布稳定版。您可以在 [这里](https://static-php.dev/) 查看。
+:::
+
 static-php-cli 是一个用于构建静态编译的 PHP 二进制的工具，目前支持 Linux 和 macOS 系统。
 
 在指南章节中，你将了解到如何使用 static-php-cli 构建独立的 php 程序。