docs: add new default field

Author: joamag

README.md

@@ -4,12 +4,12 @@ The Python based RIPE Core API client.
 
 ## Configuration
 
-| Name                | Type  | Description                                                                               |
-| ------------------- | ----- | ----------------------------------------------------------------------------------------- |
-| **RIPE_BASE_URL**   | `str` | The base URL to be used in the remote API calls (defaults to `http://localhost/api/`).    |
-| **RIPE_USERNAME**   | `str` | The username to be used in the authenticated remote calls (defaults to `None`).           |
-| **RIPE_PASSWORD**   | `str` | The password to be used in the authenticated remote calls (defaults to `None`).           |
-| **RIPE_SECRET_KEY** | `str` | The secret key to be used for stateless (no session) authentication (defaults to `None`). |
+| Name                | Type  | Default                 | Description                                                          |
+| ------------------- | ----- | ----------------------- | -------------------------------------------------------------------- |
+| **RIPE_BASE_URL**   | `str` | `http://localhost/api/` | The base URL to be used in the remote API calls.                     |
+| **RIPE_USERNAME**   | `str` | `None`                  | The username to be used in the authenticated remote calls.           |
+| **RIPE_PASSWORD**   | `str` | `None`                  | The password to be used in the authenticated remote calls.           |
+| **RIPE_SECRET_KEY** | `str` | `None`                  | The secret key to be used for stateless (no session) authentication. |
 
 ## License