[gleam][lasagna] add types

gleam/lasagna/src/lasagna.gleam

@@ -1,22 +1,19 @@
-pub fn expected_minutes_in_oven() {
+pub fn expected_minutes_in_oven() -> Int {
   40
 }
 
-pub fn remaining_minutes_in_oven(minutes: Int) {
+pub fn remaining_minutes_in_oven(minutes: Int) -> Int {
   expected_minutes_in_oven() - minutes
 }
 
-pub fn preparation_time_in_minutes(number_of_layers: Int) -> Int {
-  number_of_layers * 2
+pub fn preparation_time_in_minutes(layers: Int) -> Int {
+  layers * 2
 }
 
-pub fn total_time_in_minutes(
-  number_of_layers: Int,
-  actual_minutes_in_oven: Int,
-) -> Int {
-  preparation_time_in_minutes(number_of_layers) + actual_minutes_in_oven
+pub fn total_time_in_minutes(layers: Int, minutes_in_oven: Int) -> Int {
+  preparation_time_in_minutes(layers) + minutes_in_oven
 }
 
-pub fn alarm() {
+pub fn alarm() -> String {
   "Ding!"
 }