chore(readme): update readme

Author: chantouchsek

README.md

@@ -109,11 +109,11 @@ It will create `$errors` object inside components.
 ## Methods are available:
 
 | Validator                            | Description                                                      |
-| ------------------------------------ | ---------------------------------------------------------------- | -------------------- |
+| ------------------------------------ | ---------------------------------------------------------------- |
 | **has(field = null)**                | check specific field error                                       |
 | **first(field)**                     | get message by field name.                                       |
 | **missed(field = null)**             | check if there is no any error of given field name.              |
-| **nullState(field = null)**          | false                                                            | null of given field. |
+| **nullState(field = null)**          | Check if null of given field.                                    |
 | **any()**                            | check if any errors exist.                                       |
 | **get(field)**                       | get specific field.                                              |
 | **all()**                            | get all errors.                                                  |