unwitch-2.0.0: Changelog.md

# Change log for unwitch project

## Version 2.0.0 
+ fix cabal file links
+ delete complex module which made no sense.

## Version 1.0.0 
+ claude generate most conversion functions, looks good

## Version 0.1.0 

Implement some of Double.
Write description

## Version 0.0.0 

import [template](https://github.com/jappeace/haskell-template-project).