README.md in ruby-measurement-1.2.0 vs README.md in ruby-measurement-1.2.1

@@ -160,9 +160,15 @@
 
     Measurement.parse('3 yr')                  # => 3.0 yr
     Measurement.parse('3 year')                # => 3.0 yr
     Measurement.parse('3 years')               # => 3.0 yr
 
+### List all units names defined
+
+List all keys you can use as unit
+
+    Measurement.names                           # => ['count','doz','dozen',...]
+
 ## Contributing
 
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)