update readme

README.md

@@ -1,14 +1,66 @@
 # @agape/locale
 
-Locale settings
+Simple locale management with global state.
+
+## Installation
+
+```bash
+npm install @agape/locale
+```
+
+## Usage
+
+```typescript
+import { getLocale, setLocale } from '@agape/locale';
+
+// Get current locale
+const locale = getLocale(); // "en-US"
+
+// Set locale
+setLocale('fr-FR');
+console.log(getLocale()); // "fr-FR"
+
+// Reset to system locale
+setLocale(null);
+```
+
+## API
+
+### `getLocale(): string`
+
+Returns the current locale. If no locale has been set, returns the system locale.
+
+### `setLocale(locale: string | null | undefined): void`
+
+Sets the current locale. Pass `null` or `undefined` to reset to system locale.
+
+Throws an error if the locale is invalid.
+
+## Examples
+
+```typescript
+// Basic usage
+setLocale('es-ES');
+const current = getLocale(); // "es-ES"
+
+// Reset to system
+setLocale(null);
+const system = getLocale(); // "en-US" (or your system locale)
+
+// Error handling
+try {
+  setLocale('invalid');
+} catch (error) {
+  console.error(error.message);
+}
+```
 
 ---
 
 ## 📚 Documentation
 
 See the full API documentation at [agape.dev/api](https://agape.dev/api).
 
-
 ## 📦 Agape Toolkit
 
-This package is part of the [Agape Toolkit](https://github.com/AgapeToolkit/AgapeToolkit) - a comprehensive collection of TypeScript utilities and libraries for modern web development.
+This package is part of the [Agape Toolkit](https://github.com/AgapeToolkit/AgapeToolkit) - a comprehensive collection of TypeScript utilities and libraries for modern web development.