- redesign URL encoder/decoder with improved UI/UX

- add dark mode toggle feature
- implement proper URI component encoding with options for spaces as `+` or `%20`
- add character and byte count displays for input/output
- create toast notification system for user feedback
- add example presets for common URL encoding scenarios
- improve error handling for encode/decode operations
- add copy to clipboard functionality
- create responsive layout with better mobile support
- include informational section about URL encoding

Author: TobiasMue91