docs: Add documentation for various features including Aria2, direct download links, parsers, storage rules, silent mode, storage transfer, chat watching, and yt-dlp video download

- Created new markdown files for Aria2 download, direct download links, parsers, storage rules, silent mode, storage transfer, chat watching, and yt-dlp video download.
- Included usage examples, configuration instructions, and detailed explanations for each feature.
- Translated documentation into Chinese for accessibility.

docs/content/zh/usage/aria2.md

@@ -0,0 +1,41 @@
+---
+title: "Aria2 下载"
+weight: 6
+---
+
+# Aria2 下载
+
+{{< hint warning >}}
+该功能需要在配置文件中启用 Aria2 并配置 RPC 连接.
+{{< /hint >}}
+
+使用 `/aria2dl` 命令可以通过 Aria2 下载管理器下载文件, 支持 HTTP/HTTPS、FTP、BitTorrent 等多种协议.
+
+```bash
+/aria2dl <uri1> [uri2] [uri3] ...
+```
+
+示例:
+
+```bash
+# 下载 HTTP 链接
+/aria2dl https://example.com/file.zip
+
+# 下载磁力链接
+/aria2dl magnet:?xt=urn:btih:...
+
+# 下载种子文件 (需要先上传 .torrent 文件)
+/aria2dl https://example.com/file.torrent
+```
+
+配置 Aria2:
+
+在 `config.toml` 中添加:
+
+```toml
+[aria2]
+enable = true
+url = "http://localhost:6800/jsonrpc"
+secret = "your-rpc-secret"  # 如果配置了 rpc-secret
+remove_after_transfer = true  # 转存完成后删除本地文件
+```