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/en/usage/transfer.md

@@ -0,0 +1,50 @@
+---
+title: "Storage Transfer"
+weight: 8
+---
+
+# Storage Transfer
+
+Use the `/transfer` command to transfer files directly between different storages without going through Telegram.
+
+```bash
+/transfer <source_storage>:/<source_path> [filter]
+```
+
+Parameters:
+
+- `source_storage`: Source storage name
+- `source_path`: Source path
+- `filter`: Optional regex filter to transfer only matching files
+
+Examples:
+
+```bash
+# Transfer entire directory
+/transfer local1:/downloads
+
+# Transfer files from specified path
+/transfer alist1:/media/photos
+
+# Transfer only mp4 files
+/transfer webdav1:/videos ".*\.mp4$"
+
+# Transfer image files
+/transfer local1:/pictures "(?i)\.(jpg|png|gif)$"
+```
+
+The bot will:
+
+1. List all files in the source path
+2. Apply the filter (if provided)
+3. Display file count and total size
+4. Ask you to select the target storage
+5. Ask you to select the target directory (if configured for that storage)
+6. Start the transfer task
+
+Notes:
+
+- Source storage must support listing and reading
+- Target storage must support writing
+- Real-time progress is displayed during transfer
+- Transfer tasks can be cancelled