docs: update changelog format

CHANGELOG.md

@@ -1,35 +1,35 @@
-## [0.5.1] - Aug 8, 2022
+## 0.5.1
 
 - Add example.dart
 
-## [0.5.0] - Aug 8, 2022
+## 0.5.0
 
 - General code improvement + finalize null safety support
 
-## [0.0.7-nullsafety] - Jul 10, 2021
+## 0.0.7-nullsafety
 
 - No changes
 
-## [0.0.6-nullsafety] - Jul 30, 2021
+## 0.0.6-nullsafety
 
 - Updated the package for null-safety
 
-## [0.0.6] - 22 Mar, 2019
+## 0.0.6
 
 - Added style customization options
 
-## [0.0.5] - 22 Mar, 2019
+## 0.0.5
 
 - Added finger fling physics to control
 
-## [0.0.3-0.0.4] - 10 Mar, 2019
+## 0.0.3-0.0.4
 
 - Bugfixes
 
-## [0.0.2] - 10 Mar, 2019
+## 0.0.2
 
 - Added `minMaxLabelBuilder`
 
-## [0.0.1] - 10 Mar, 2019
+## 0.0.1
 
 - Initial release