Update CHANGELOG.md
Update CHANGELOG.md

New version 2.1 after adding support for python lower and new versions.
AnimeshShaw/Hash-Algorithm-Identifier,chikiru900/Hash-Algorithm-Identifier,chikiru900/Hash-Algorithm-Identifier,AnimeshShaw/Hash-Algorithm-Identifier,sigma-random/Hash-Algorithm-Identifier,sigma-random/Hash-Algorithm-Identifier