updated changeset copy

Author: Rmnlly

.changeset/tidy-waves-live.md

@@ -2,4 +2,4 @@
 '@shopify/polaris': minor
 ---
 
-A new prop has been added (truncateText) to allow navigation item text to be truncated instead of flowing onto multiple lines
+Added `truncateText` prop to `Navigation.Item` to prevent text wrapping