(DOCS-8048) Adds default value for timeout (#17618)

* (DOCS-8048) Adds default value for timeout

* Update http_check/README.md

Co-authored-by: Jen Gilbert <jen.gilbert@datadoghq.com>

---------

Co-authored-by: Jen Gilbert <jen.gilbert@datadoghq.com>

Author: neko-dd

http_check/README.md

@@ -35,7 +35,7 @@ See the [sample http_check.d/conf.yaml][3] for a full list and description of av
 | -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
 | `name`                           | Name of your Http check instance. This is presented as a tag on the Service Checks.                                                                                                                                                              |
 | `url`                            | The URL to test.                                                                                                                                                                                                                                 |
-| `timeout`                        | The time in seconds to allow for a response.                                                                                                                                                                                                     |
+| `timeout`                        | The time in seconds to allow for a response. The default is `10`.                                                                                                                                                                               |
 | `method`                         | The HTTP method to use for the check.                                                                                                                                                                                                            |
 | `data`                           | Use this parameter to specify a body for a request with a POST, PUT, DELETE, or PATCH method. SOAP requests are supported if you use the POST method and supply an XML string as the data parameter.                                             |
 | `headers`                        | This parameter allows you to send additional headers with the request. See the [example YAML file][3] for additional information and caveats.                                                                                                    |