Update CHANGELOG for 1.3.1 release

Author: barchetta

CHANGELOG.md

@@ -5,12 +5,13 @@ All notable changes to this project will be documented in this file.
 
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased] 
+## [1.3.1] 
 
 ### Notes
 
 This is a bugfix release. It fixes a Helidon MP 
-configuration regression on Windows: [1038](https://github.com/oracle/helidon/issues/1038).
+configuration regression on Windows: [1038](https://github.com/oracle/helidon/issues/1038), as
+well as other fixes listed below.
 
 ### Fixes
 
@@ -25,6 +26,7 @@ configuration regression on Windows: [1038](https://github.com/oracle/helidon/is
 - Fixes a reference to a non-existent ResourceBundle [1058](https://github.com/oracle/helidon/pull/1058)
 - Add exclusions for org.osgi:org.osgi.annotation.versioning [1034](https://github.com/oracle/helidon/pull/1034)
 - Documentation fixes [1043](https://github.com/oracle/helidon/pull/1043) [1053](https://github.com/oracle/helidon/pull/1053) 
+- Documentation: add tracing guides [1023](https://github.com/oracle/helidon/pull/1023) [1014](https://github.com/oracle/helidon/pull/1014)
 - Examples fixes [1056](https://github.com/oracle/helidon/pull/1056)
 - Build fixes [1027](https://github.com/oracle/helidon/pull/1027) [1033](https://github.com/oracle/helidon/pull/1033) [1035](https://github.com/oracle/helidon/pull/1035)
 
@@ -503,7 +505,7 @@ for details.
 ### Notes
 - Initial source drop on Github
 
-[Unreleased]: https://github.com/oracle/helidon/compare/1.3.0...HEAD
+[1.3.1]: https://github.com/oracle/helidon/compare/1.3.0...1.3.1
 [1.3.0]: https://github.com/oracle/helidon/compare/1.2.1...1.3.0
 [1.2.1]: https://github.com/oracle/helidon/compare/1.2.0...1.2.1
 [1.2.0]: https://github.com/oracle/helidon/compare/1.1.2...1.2.0