Fix typo in elons-toys (#2342)

exercises/concept/elons-toys/.docs/introduction.md

@@ -35,7 +35,7 @@ class Car
 }
 ```
 
-One can optionally assign an initial value to a field. If a field does _not_ specify an initial value, it wll be set to its type's default value. An instance's field values can be accessed and updated using dot-notation.
+One can optionally assign an initial value to a field. If a field does _not_ specify an initial value, it will be set to its type's default value. An instance's field values can be accessed and updated using dot-notation.
 
 ```csharp
 class Car