docs(i18n): add Persian language docs link (vitejs#20024)

Author: mostafa-nematpour

docs/.vitepress/config.ts

@@ -136,6 +136,7 @@ export default defineConfig({
     pt: { label: 'Português', link: 'https://pt.vite.dev' },
     ko: { label: '한국어', link: 'https://ko.vite.dev' },
     de: { label: 'Deutsch', link: 'https://de.vite.dev' },
+    fa: { label: 'فارسی', link: 'https://fa.vite.dev' },
   },
 
   themeConfig: {