Export wrapTextWithAnsi utility and add handleInput docs

- Export wrapTextWithAnsi from tui package
- Add 'Handling Input' section to README with key detection example
- Document wrapTextWithAnsi in utilities section

packages/tui/src/index.ts

@@ -85,4 +85,4 @@ export {
 } from "./terminal-image.js";
 export { type Component, Container, TUI } from "./tui.js";
 // Utilities
-export { truncateToWidth, visibleWidth } from "./utils.js";
+export { truncateToWidth, visibleWidth, wrapTextWithAnsi } from "./utils.js";