docs: add changeset

Author: bennypowers

.changeset/pf-helper-text.md

@@ -0,0 +1,11 @@
+---
+"@patternfly/elements": minor
+---
+
+✨ Added `<pf-helper-text>` element
+
+**Helper text** is an on-screen field guideline that helps provide context regarding field inputs.
+
+```html
+<pf-helper-text variant="error">You must include an email address</pf-helper-text>
+```