feat: Add support for Spanish language option in WebUI Settings

src/lib/i18n/locales/languages.json

@@ -11,6 +11,10 @@
 		"code": "de-DE",
 		"title": "Deutsch"
 	},
+	{
+		"code": "es-ES",
+		"title": "Spanish"
+	},
 	{
 		"code": "fr-FR",
 		"title": "French (France)"