chore(README): Add required docs to README.md (#703)

README.md

@@ -458,6 +458,7 @@ type Foo struct {
 
 Field Name | Type | Description
 ---|:---:|---
+<a name="validate"></a>validate | `string` | 	Determines the validation for the parameter. Possible values are: `required`. 
 <a name="parameterDefault"></a>default | * | Declares the value of the parameter that the server will use if none is provided, for example a "count" to control the number of results per page might default to 100 if not supplied by the client in the request. (Note: "default" has no meaning for required parameters.)  See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-6.2. Unlike JSON Schema this value MUST conform to the defined [`type`](#parameterType) for this parameter.
 <a name="parameterMaximum"></a>maximum | `number` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.2.
 <a name="parameterMinimum"></a>minimum | `number` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.3.