Add download file service to Telegram bot integration

source/_integrations/telegram_bot.markdown

@@ -18,7 +18,7 @@ ha_platforms:
 ---
 
 Use Telegram on your mobile or desktop device to send and receive messages or commands to/from your Home Assistant.
-This integration creates notification actions to send, edit or receive messages from a [Telegram Bot account](https://core.telegram.org/bots).
+This integration creates notification actions to send, edit, receive messages or download attachments from a [Telegram Bot account](https://core.telegram.org/bots).
 
 ## Introduction - Telegram bot platforms
 
@@ -530,6 +530,36 @@ Sets the bot's reaction for a given message.
 | `reaction`          | no       | Emoji to react to the message with. |
 | `is_big`            | yes      | Whether to use a large variant of the reaction animation.        |
 
+### Action `telegram_bot.download_file`
+
+Download a file previously sent to the bot and save it to a local path on the Home Assistant host.
+
+| Data attribute   | Optional | Description |
+| ---------------- | -------- | ----------- |
+| `config_entry_id`| yes      | The config entry representing the Telegram bot to get the file. Required if you have multiple Telegram bots. |
+| `file_id`        | no       | ID of the file to get. This is provided in `telegram_attachment` event data as `file_id`. |
+| `directory_path` | yes      | Local directory path to save the file to. Defaults to `/config/telegram_bot/`. |
+| `file_name`      | yes      | Name to save the file as. If not provided, the original file name will be used. |
+
+Example YAML usage:
+
+```yaml
+action: telegram_bot.download_file
+data:
+  config_entry_id: "<your_config_entry_id>"
+  file_id: "ABCD1234Efgh5678Ijkl90mnopQRStuvwx"
+  directory_path: "/config/telegram_bot/"
+  file_name: "my_downloaded_file"
+```
+
+{% note %}
+
+- For file size limits and download behavior, refer to the python-telegram-bot documentation: [python-telegram-bot - get_file](https://docs.python-telegram-bot.org/en/stable/telegram.bot.html#telegram.Bot.get_file)
+- For the moment, bots can download files of up to 20 MB in size.
+- Ensure the target `directory_path` is included in `allowlist_external_dirs` if you need to serve or access the file from the frontend.
+
+{% endnote %}
+
 ## Response schemas for actions
 
 {% tip %}