feat: add kratos webhook header allowlist config details (#2100)

* feat: add kratos webhook header allowlist config details

Signed-off-by: Mia <m@yarn.network>

* fix: wording

Signed-off-by: Mia <m@yarn.network>

---------

Signed-off-by: Mia <m@yarn.network>

Author: K3das

docs/guides/integrate-with-ory-cloud-through-webhooks.mdx

@@ -91,7 +91,7 @@ template as well. These objects are available through a `ctx` object.
 
 #### Accessing request headers
 
-The following request headers are available via `ctx.request_headers`:
+Request headers are available via `ctx.request_headers`. By default, only the following headers are exposed:
 
 ```
 Accept
@@ -113,6 +113,8 @@ True-Client-Ip
 User-Agent
 ```
 
+To customize allowed headers, use the `actions.web_hook.header_allowlist` configuration option.
+
 #### Jsonnet templating
 
 To send `{ user_id: {some-id} }` in the request body, create the following the [Jsonnet](https://jsonnet.org) template: