feat: Add dashboard support and enhance Discord webhook functionality

- Updated docker-compose.yml to expose dashboard on port 8080.
- Enhanced main.py with timezone database caching and improved state management.
- Introduced a minimal dashboard using Flask to display webhook status and notifications.
- Added templates.json for customizable embed messages in Discord notifications.
- Created templates.py for loading and saving notification templates.
- Implemented tests for dashboard rendering and main functionality.
- Added requirements for Flask and tzdata to support new features.
- Included test cases for timezone handling and template management.

README.md

@@ -11,16 +11,21 @@ This Python application sends notifications to a Discord channel via webhook eve
    ```
 
 2. Set up your Discord webhook:
-
    - Go to your Discord server settings > Integrations > Webhooks
    - Create a new webhook and copy the URL
 
-3. Update the `.env` file with your webhook URL:
+3. Update the `.env` file with your webhook URL, bot token, channel ID, and guild ID:
 
    ```text
    DISCORD_WEBHOOK_URL=https://discord.com/api/webhooks/your_webhook_id/your_webhook_token
+   DISCORD_BOT_TOKEN=your_bot_token
+   DISCORD_CHANNEL_ID=your_channel_id
+   DISCORD_GUILD_ID=your_guild_id
    ```
 
+   - To get a bot token, create a Discord bot in the [Discord Developer Portal](https://discord.com/developers/applications) and invite it to your server with the `Manage Messages` permission.
+   - The channel ID can be found by enabling Developer Mode in Discord and right-clicking the channel name.
+
 ## Running the App
 
 Run the application:
@@ -31,6 +36,19 @@ python main.py
 
 The app will run continuously and send notifications at the scheduled times.
 
+### Dashboard
+
+By default, a minimal dashboard is available at `http://localhost:8080/`.
+
+You can disable it by setting `DASHBOARD_ENABLED=0`.
+
+### Admin
+
+You can edit the embed message templates at `http://localhost:8080/admin`.
+
+- Templates are saved to `templates.json` by default.
+- Override the location with `TEMPLATES_PATH=/path/to/templates.json`.
+
 ## Requirements
 
 - Python 3.6+