Update Changelog.md (#645)

Update Changelog.md with #636

Author: MarcoRossignoli

Documentation/Changelog.md

@@ -16,7 +16,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 -Fix and simplify async coverage [#549](https://github.com/tonerdo/coverlet/pull/549)  
 -Improve lambda scenario coverage [#583](https://github.com/tonerdo/coverlet/pull/583)  
 -Mitigate issue in case of failure in assembly loading by cecil [#625](https://github.com/tonerdo/coverlet/pull/625)  
--Fix ConfigureAwait state machine generated branches [#634](https://github.com/tonerdo/coverlet/pull/634)
+-Fix ConfigureAwait state machine generated branches [#634](https://github.com/tonerdo/coverlet/pull/634)  
+-Fix Coverage is overwritten if the project has multiple target frameworks [#636](https://github.com/tonerdo/coverlet/issues/177)  
 
 ### Improvements