docs: remove vim/neovim docs, update links to separate repo

Author: yhk1038

README.ja.md

@@ -252,8 +252,7 @@ watch:
 **IDE サポート**
 - [VS Code 拡張 (および Cursor)](https://github.com/type-ruby/t-ruby-vscode)
 - [JetBrains プラグイン](https://github.com/type-ruby/t-ruby-jetbrains)
-- [Vim セットアップ](./docs/vim/ja/getting-started.md)
-- [Neovim セットアップ](./docs/neovim/ja/getting-started.md)
+- [Vim / Neovim](https://github.com/type-ruby/t-ruby-vim)
 
 **ガイド**
 - [シンタックスハイライト](./docs/syntax-highlighting/ja/guide.md)

README.ko.md

@@ -252,8 +252,7 @@ watch:
 **IDE 지원**
 - [VS Code 확장 (및 Cursor)](https://github.com/type-ruby/t-ruby-vscode)
 - [JetBrains 플러그인](https://github.com/type-ruby/t-ruby-jetbrains)
-- [Vim 설정](./docs/vim/ko/getting-started.md)
-- [Neovim 설정](./docs/neovim/ko/getting-started.md)
+- [Vim / Neovim](https://github.com/type-ruby/t-ruby-vim)
 
 **가이드**
 - [구문 강조](./docs/syntax-highlighting/ko/guide.md)

README.md

@@ -257,8 +257,7 @@ watch:
 **IDE Support**
 - [VS Code Extension (and Cursor)](https://github.com/type-ruby/t-ruby-vscode)
 - [JetBrains Plugin](https://github.com/type-ruby/t-ruby-jetbrains)
-- [Vim Setup](./docs/vim/en/getting-started.md)
-- [Neovim Setup](./docs/neovim/en/getting-started.md)
+- [Vim / Neovim](https://github.com/type-ruby/t-ruby-vim)
 
 **Guides**
 - [Syntax Highlighting](./docs/syntax-highlighting/en/guide.md)