Update release.md

[da1suk8]

The release.md file is referring to non-existent files (.github/changelog.yml), and the content of the document has not been updated, so it needs to be updated.

FYI: you can check .github/changelog.yml at https://github.com/Finschia/cosmwasm/pull/108/commits/876de45868b56bc72047b892fcf2ac157182f02d