Docs: Clarify autocapture allowlist (#10924)

* Documentation updates from Promptless

---------

Co-authored-by: promptless[bot] <179508745+promptless[bot]@users.noreply.github.com>
Co-authored-by: Ian Vanagas <34755028+ivanagas@users.noreply.github.com>

Author: promptless[bot]

contents/docs/product-analytics/autocapture.mdx

@@ -50,6 +50,8 @@ posthog.init('<ph_project_api_key>', {
 ```
 Allow and ignorelists only filter autocapture events. They don't affect the data collected by session recordings or custom events.
 
+> **Note:** When using `element_allowlist` or `css_selector_allowlist`, PostHog considers the entire tree of elements from the root to the target element of the click event, not just the element that was directly clicked. If *any* element or selector is in the tree *and* allow list, the click is captured.
+
 ### Preventing sensitive data capture
 
 For security reasons and to prevent sensitive data capture, PostHog is conservative about capturing `input` tags. We specifically only collect the `name`, `id`, and `class` attributes from `input` tags. If you need to collect more data from inputs, you should use [custom events](/docs/product-analytics/capture-events).