feat: update README and improve ESLint configuration

- Updated the Chat UI-Backend Architecture section in README.md to reflect new message rendering logic.
- Enhanced the ESLint configuration by refining ignored files and updating TypeScript ESLint plugin usage.
- Changed AccordionTriggerProps and AccordionContentProps from interface to type for consistency in ui/accordion.tsx.
- Updated TabsListProps from interface to type for consistency in ui/tabs.tsx.