Update CHANGELOG.md

Add entry for version 18.1.1.
Include fixes for `NumberValidator` related to decimal numbers.

Author: joanpablo

CHANGELOG.md

@@ -1,3 +1,9 @@
+# 18.1.1
+
+## Fixes
+- Fix `NumberValidator` to correctly handle decimal numbers with trailing zeros.
+- Improve `NumberValidator` to correctly validate numbers with multiple decimal points, single dot, and dot at the end.
+
 # 18.1.0
 
 - Add `oneOf` validator to the list of validators.
@@ -1000,4 +1006,4 @@ to migrate from version 1.x to 2.x.
 
 - ReactiveForm
 - ReactiveFormConsumer
-- ReactiveValueListenableBuilder
+- ReactiveValueListenableBuilder