docs: add storage guide for plugins in English and Chinese

Author: Soulter

.vitepress/config.mjs

@@ -190,6 +190,7 @@ export default defineConfig({
                   { text: "发送消息", link: "/guides/send-message" },
                   { text: "插件配置", link: "/guides/plugin-config" },
                   { text: "调用 AI", link: "/guides/ai" },
+                  { text: "存储", link: "/guides/storage" },
                   { text: "文转图", link: "/guides/html-to-pic" },
                   { text: "会话控制器", link: "/guides/session-control" },
                   { text: "杂项", link: "/guides/other" },
@@ -410,6 +411,7 @@ export default defineConfig({
                   { text: "Send Messages", link: "/guides/send-message" },
                   { text: "Plugin Configuration", link: "/guides/plugin-config" },
                   { text: "AI", link: "/guides/ai" },
+                  { text: "Storage", link: "/guides/storage" },
                   { text: "HTML to Image", link: "/guides/html-to-pic" },
                   { text: "Session Control", link: "/guides/session-control" },
                   { text: "Publish Plugin", link: "/plugin-publish" },

en/dev/star/guides/storage.md

@@ -0,0 +1,31 @@
+# Plugin Storage
+
+## Simple KV Storage
+
+> [!TIP]
+> Requires AstrBot version >= 4.9.2.
+
+Plugins can use AstrBot's simple key-value store to persist configuration or temporary data. The storage is scoped per plugin, so each plugin has its own isolated space.
+
+```py
+class Main(star.Star):
+    @filter.command("hello")
+    async def hello(self, event: AstrMessageEvent):
+        """Aloha!"""
+        await self.put_kv_data("greeted", True)
+        greeted = await self.get_kv_data("greeted", False)
+        await self.delete_kv_data("greeted")
+```
+
+
+## Large File Storage Convention
+
+To keep large file handling consistent, store large files under `data/plugin_data/{plugin_name}/`.
+
+You can fetch the plugin data directory with:
+
+```py
+from astrbot.core.utils.astrbot_path import get_astrbot_data_path
+
+plugin_data_path = get_astrbot_data_path() / "plugin_data" / self.name  # self.name is the plugin name; available in v4.9.2 and above. For lower versions, specify the plugin name yourself.
+```

zh/dev/star/guides/storage.md

@@ -0,0 +1,31 @@
+# 插件存储
+
+## 简单 KV 存储
+
+> [!TIP]
+> 该功能需要 AstrBot 版本 >= 4.9.2。
+
+插件可以使用 AstrBot 提供的简单 KV 存储功能来存储一些配置信息或临时数据。该存储是基于插件维度的，每个插件有独立的存储空间，互不干扰。
+
+```py
+class Main(star.Star):
+    @filter.command("hello")
+    async def hello(self, event: AstrMessageEvent):
+        """Aloha!"""
+        await self.put_kv_data("greeted", True)
+        greeted = await self.get_kv_data("greeted", False)
+        await self.delete_kv_data("greeted")
+```
+
+
+## 存储大文件规范
+
+为了规范插件存储大文件的行为，请将大文件存储于 `data/plugin_data/{plugin_name}/` 目录下。
+
+你可以通过以下代码获取插件数据目录：
+
+```py
+from astrbot.core.utils.astrbot_path import get_astrbot_data_path
+
+plugin_data_path = get_astrbot_data_path() / "plugin_data" / self.name # self.name 为插件名称，在 v4.9.2 及以上版本可用，低于此版本请自行指定插件名称
+```