fix: made i18n example use the right locales function

I made the mistake I explicitly documented about how to not make. Once
again, I can *occasionally* convince myself that I have any clue of what
I'm doing. Now is not one of those moments.

examples/core/i18n/src/lib.rs

@@ -8,6 +8,7 @@ pub fn main<G: Html>() -> PerseusApp<G> {
     PerseusApp::new()
         .template(crate::templates::index::get_template)
         .template(crate::templates::about::get_template)
+        .template(crate::templates::post::get_template)
         .error_pages(crate::error_pages::get_error_pages)
-        .locales("en-US", &["fr-FR", "es_ES"])
+        .locales_and_translations_manager("en-US", &["fr-FR", "es-ES"])
 }