Add stub file

Author: meatball133

exercises/concept/freelancer-rates/src/FreelancerRates.hs

@@ -4,11 +4,10 @@ dailyRate :: Double -> Double
 dailyRate = error "Implement this function."
 
 applyDiscount :: Double -> Double -> Double 
-applyDiscount amount disscount = amount * (1 - disscount / 100)
+applyDiscount = error "Implement this function."
 
 monthlyRate :: Double -> Double -> Int
-monthlyRate hourlyRate discount = ceiling (applyDiscount (dailyRate hourlyRate * 22) discount)
+monthlyRate = error "Implement this function."
 
 daysInBudget :: Int -> Double -> Double -> Double
-daysInBudget budget hourlyRate discount = 
-    fromIntegral (floor (fromIntegral budget / applyDiscount (dailyRate hourlyRate) discount * 10)) / 10
+daysInBudget = error "Implement this function."