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.

templates.json

@@ -0,0 +1,20 @@
+{
+  "420": {
+    "color": 3066993,
+    "image_url": "https://copyparty.allucanget.biz/img/weed.png",
+    "text": "Blaze it!"
+  },
+  "halftime": {
+    "color": 3066993,
+    "image_url": "https://copyparty.allucanget.biz/img/weed.png",
+    "text": "Half-time!"
+  },
+  "reminder": {
+    "color": 15105570,
+    "text": "This is your 5 minute reminder to 420!"
+  },
+  "reminder_halftime": {
+    "color": 15105570,
+    "text": "Half-time in 5 minutes!"
+  }
+}