CHANGELOG in pdf-reader-2.9.0 vs CHANGELOG in pdf-reader-2.9.1

@@ -1,4 +1,8 @@
+v2.9.1 (4th February 2022)
+- Fix exception in Page#walk introduced in 2.9.0 (http://github.com/yob/pdf-reader/pull/442)
+- Other small bug fixes
+
 v2.9.0 (24th January 2022)
 - Support additional encryption standards (http://github.com/yob/pdf-reader/pull/419)
 - Return CropBox correctly from Page#rectangles (https://github.com/yob/pdf-reader/pull/420)
 - For sorbet users, additional type annotations are included in the gem