Refactor: Improve error message

The error message now shows the invalid value

Author: xetxeberria

exercises/tiered_pricing/solutions/xetxeberria-ts/src/tieredPricing.ts

@@ -9,7 +9,7 @@ const priceTiers = [
 export function tieredPricing(licenseAmount: number): number {
   if (licenseAmount < 0)
     throw new Error(
-      "Invalid license amount. License amount can not be negative"
+      `Invalid license amount <${licenseAmount}>. License amount can not be negative`
     );
 
   const licensePrice = calculateLicensePrice(licenseAmount);