feat: Add healtcheck endpoint

internal/api/api.go

@@ -50,6 +50,9 @@ func New(services Services) *fiber.App {
 	)
 
 	cacheHeader := fmt.Sprintf("max-age=%0f", (time.Hour * 24).Seconds())
+	app.Get("/healthz", func(ctx *fiber.Ctx) error {
+		return ctx.SendString("OK")
+	})
 	app.Get("/diyanet/prayertimes", func(ctx *fiber.Ctx) error {
 		locationID := ctx.Query("location_id")