README_V3.md in schemacop-3.0.0 vs README_V3.md in schemacop-3.0.1

@@ -239,9 +239,12 @@
   The string must be an integer and will be casted to a ruby `Integer` object.
 
 * `number`
   The string must be a number and will be casted to a ruby `Float` object.
 
+* `symbol`
+  The string can be anything and will be casted to a ruby `Symbol` object.
+
 #### Examples
 
 ```ruby
 # By using a format, string values are casted to that respective format
 schema = Schemacop::Schema3.new(:string, format: :date)