docs: update README with Test Mode and Auto-update features

- Added Test Mode documentation for safe development
- Added Auto-updates feature description
- Added usage instructions for testing mode

README.md

@@ -11,6 +11,8 @@ A Discord bot that reads messages aloud using [Pocket TTS](https://github.com/ky
 - 🔄 **Per-User Voice Selection**: Each user can choose their own TTS voice via `/voice` commands
 - 💾 **Voice Persistence**: User voice preferences are saved and restored on restart
 - 🔄 **Hot-reload Voices**: Add new voices without restarting the bot using `/voice refresh`
+- 🧪 **Test Mode**: Separate testing configuration for safe development
+- 📦 **Auto-updates**: Automatically checks for and installs dependency updates on startup
 
 ## Prerequisites
 
@@ -108,6 +110,21 @@ A Discord bot that reads messages aloud using [Pocket TTS](https://github.com/ky
    - `/voice current` - Shows your current voice
    - `/voice refresh` - Re-scan for new voice files (no restart needed)
 
+### Test Mode
+
+Run the bot in testing mode to use a separate configuration:
+
+```bash
+python bot.py testing
+```
+
+This loads `.env.testing` instead of `.env`, allowing you to:
+- Use a different Discord bot token for testing
+- Monitor a different text channel
+- Test new features without affecting the production bot
+
+Create `.env.testing` by copying `.env.example` and configuring it with your testing values.
+
 ## How It Works
 
 ```