feat: add landing page copy and styles for English and Amharic versions

- Introduced `landing-copy.ts` containing text for the public landing page, supporting both English and Amharic languages.
- Added `landing.css` for styling the landing page, ensuring scoped styles to prevent conflicts with other app styles.
- Implemented smooth scrolling and animations for a better user experience.

libs/ui/src/index.ts

@@ -21,3 +21,5 @@ export * from "./lib/input/phone";
 export * from "./lib/data/AdvancedTable";
 export * from "./lib/feedback/use-error-handler";
 export * from "./lib/data/useServerTable";
+export * from "./lib/landing/LandingPage";
+export * from "./lib/landing/landing-copy";