docs: add comprehensive static daily reminders documentation

- Add static daily reminders to README.md core features and API reference
- Create detailed usage guide in USAGE.md with examples and best practices
- Add version 2.1.0 changelog entry documenting new reminder functionality
- Create examples/static-daily-reminders.ts with complete usage examples
- Update test-apps README to include reminder testing capabilities

The static daily reminder feature provides simple daily notifications
without network content dependency, supporting cross-platform scheduling
with rich customization options.

CHANGELOG.md

@@ -5,6 +5,40 @@ All notable changes to the Daily Notification Plugin will be documented in this
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.1.0] - 2025-01-02
+
+### Added
+
+- **Static Daily Reminders**: New functionality for simple daily notifications without network content
+- **Cross-Platform Reminder API**: Consistent reminder management across Android, iOS, and Web
+- **Reminder Management**: Full CRUD operations for reminder scheduling and management
+- **Offline Reminder Support**: Reminders work completely offline without content caching
+- **Rich Reminder Customization**: Support for custom titles, bodies, sounds, vibration, and priorities
+- **Persistent Reminder Storage**: Reminders survive app restarts and device reboots
+
+### New Methods
+
+- `scheduleDailyReminder(options)`: Schedule a simple daily reminder
+- `cancelDailyReminder(reminderId)`: Cancel a specific reminder
+- `getScheduledReminders()`: Get all scheduled reminders
+- `updateDailyReminder(reminderId, options)`: Update an existing reminder
+
+### Features
+
+- **No Network Dependency**: Static reminders work completely offline
+- **Simple Time Format**: Easy HH:mm time format (e.g., "09:00")
+- **Priority Levels**: Support for low, normal, and high priority notifications
+- **Repeat Options**: Configurable daily repetition
+- **Platform Integration**: Native notification channels and categories
+- **Test App Integration**: Complete test app support for reminder functionality
+
+### Documentation
+
+- Updated README.md with static reminder examples and API reference
+- Added comprehensive usage examples in USAGE.md
+- Created detailed example file: `examples/static-daily-reminders.ts`
+- Enhanced test apps with reminder management UI
+
 ## [1.0.0] - 2024-03-20
 
 ### Added