feat: improve release notes markdown rendering (#148)

- Add react-markdown and remark-gfm for proper markdown parsing
- Add @tailwindcss/typography plugin for prose styling
- Replace plain text rendering with custom ReactMarkdown components
- Headers now render with proper sizing and hierarchy
- Lists display with bullets and proper indentation
- Links are clickable and styled appropriately
- Emojis render correctly
- Maintain dark mode compatibility

Author: michelroegl-brunner