README.md in cevennes-1.0.0 vs README.md in cevennes-1.1.0

@@ -7,11 +7,11 @@
 Diffs CSVs by lines, focusing on a single ID
 
 
 ## usage
 
-Given two CSV strings and an identifier name, cevennes may compute a diff:
+Given two CSV strings and an identifier name (a column name), cevennes may compute a diff:
 ```ruby
 require 'cevennes'
 
 cvs0 = %{
   id,name,age
@@ -25,9 +25,12 @@
   1,Jean-Baptiste,44
   4,Matthew,20
 }.strip + "\n"
 
 d = Cevennes.diff('id', cvs0, cvs1)
+
+#d = Cevennes.diff('id', cvs0, cvs1, ignore_key_case: true)
+  # when the key case should be ignored ("Id" == "id")
 ```
 
 `d` will yield:
 ```ruby
 [