edits

README.md

@@ -5,7 +5,6 @@ Adds a `With` method to immutable objects that constructs a new 'mutation' of th
 # Simple Usage
 
 Define an immutable class and mark it as such by inheriting interface Immutable:
-
 ```
 public class Employee : IImmutable {
   public string FirstName { get; }
@@ -14,6 +13,7 @@ public class Employee : IImmutable {
   public Employee(string firstName, string lastName) { FirstName = firstName; LastName = lastName; }
 }
 ```
+Note that parameter names in our constructor *must* match fields names except for the first letter which can have a different case (ie `firstName` for field `FirstName`) 
 
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