Add a last updated section to component attributes (#24646)

* Add a last updated section to component attributes

* Update src/content/docs/style-guide/documentation-content-strategy/component-attributes/last-updated.mdx

Co-authored-by: Pedro Sousa <[email protected]>

---------

Co-authored-by: Pedro Sousa <[email protected]>

Author: haleycode

src/content/docs/style-guide/documentation-content-strategy/component-attributes/last-updated.mdx

@@ -0,0 +1,19 @@
+---
+pcx_content_type: concept
+title: Last Updated
+
+---
+
+## Definition
+
+A date displayed at the bottom of each page that shows when the content on the page was last modified. This date is pulled from the page's Git history and does not account for modifications to embedded content such as partials.
+
+The Last Updated date will be refreshed for any change to a page's content, while the [Reviewed](/style-guide/frontmatter/custom-properties/#reviewed) property indicates when the page was last explicitly reviewed from beginning to end.
+
+## Used in
+
+All page types.
+
+## Structure
+
+Mon DD, YYYY