v2.0.0
Migrate to null saftey (#5) * migrate to null saftey * remove unnecessary files * [Amend] Ignore directories created by editor * [Trivial] Change CHANGELOG Reverse version order cause it's more easy to read * [Update] Change linter to "lints" Previous linter "pedantic" is deprecated so change to lints as recommandation. * [Trivial] Code formatting Co-authored-by: Sugyo-In <sgin0821@gmail.com>