fix: confusing wording for billing cycle

docs: update screenshots on readme

includes/i18n/es.php

@@ -42,6 +42,10 @@ $i18n = [
     "Weekly"          => "Semanal",
     "Monthly"         => "Mensual",
     "Yearly"          => "Anual",
+    "daily"           => "Día(s)",
+    "weekly"          => "Semana(s)",
+    "monthly"         => "Mes(es)",
+    "yearly"          => "Año(s)",
     "days"            => "días",
     "weeks"           => "semanas",
     "months"          => "meses",
@@ -58,7 +62,7 @@ $i18n = [
     "search_logo"     => "Buscar logotipo en la web",
     "web_search"      => "Búsqueda web",
     "currency"        => "Moneda",
-    "billing_cycle"   => "Ciclo de Facturación",
+    "payment_every"   => "Pago cada",
     "frequency"       => "Frecuencia",
     "cycle"           => "Ciclo",
     "next_payment"    => "Próximo Pago",