Merge branch 'pagelayout-hidden-prop' of github.com:primer/react into pagelayout-hidden-prop

Author: colebemis

.changeset/empty-garlics-clean.md

@@ -0,0 +1,10 @@
+---
+"@primer/react": minor
+---
+
+Add a responsive `hidden` prop to `PageLayout.Header`, `PageLayout.Pane`, `PageLayout.Content`, and `PageLayout.Footer` that allows you to hide layout regions based on the viewport width. Example usage:
+
+```jsx
+// Hide pane on narrow viewports
+<PageLayout.Pane hidden={{narrow: true}}>...</PageLayout.Pane>
+```