docs: add read_data info to docs

Author: detvdl

docs/resources/object.md

@@ -40,6 +40,7 @@ resource "restapi_object" "Foo2" {
 - `id_attribute` (String) Defaults to `id_attribute` set on the provider. Allows per-resource override of `id_attribute` (see `id_attribute` provider config documentation)
 - `object_id` (String) Defaults to the id learned by the provider during normal operations and `id_attribute`. Allows you to set the id manually. This is used in conjunction with the `*_path` attributes.
 - `query_string` (String) Query string to be included in the path
+- `read_data` (String) Valid JSON object to pass during read requests.
 - `read_method` (String) Defaults to `read_method` set on the provider. Allows per-resource override of `read_method` (see `read_method` provider config documentation)
 - `read_path` (String) Defaults to `path/{id}`. The API path that represents where to READ (GET) objects of this type on the API server. The string `{id}` will be replaced with the terraform ID of the object.
 - `read_search` (Map of String) Custom search for `read_path`. This map will take `search_key`, `search_value`, `results_key` and `query_string` (see datasource config documentation)