Update validate fn param docs (#526)

README.md

@@ -108,7 +108,7 @@ A question object is a `hash` containing question related values:
 - **default**: (String|Number|Array|Function) Default value(s) to use if nothing is entered, or a function that returns the default value(s). If defined as a function, the first parameter will be the current inquirer session answers.
 - **choices**: (Array|Function) Choices array or a function returning a choices array. If defined as a function, the first parameter will be the current inquirer session answers.
 Array values can be simple `strings`, or `objects` containing a `name` (to display in list), a `value` (to save in the answers hash) and a `short` (to display after selection) properties. The choices array can also contain [a `Separator`](#separator).
-- **validate**: (Function) Receive the user input and should return `true` if the value is valid, and an error message (`String`) otherwise. If `false` is returned, a default error message is provided.
+- **validate**: (Function) Receive the user input and answers hash. Should return `true` if the value is valid, and an error message (`String`) otherwise. If `false` is returned, a default error message is provided.
 - **filter**: (Function) Receive the user input and return the filtered value to be used inside the program. The value returned will be added to the _Answers_ hash.
 - **when**: (Function, Boolean) Receive the current user answers hash and should return `true` or `false` depending on whether or not this question should be asked. The value can also be a simple boolean.
 - **pageSize**: (Number) Change the number of lines that will be rendered when using `list`, `rawList`, `expand` or `checkbox`.