Add Setup Vim/Neovim Action

[rhysd]

action-setup-vim is an action to setup Vim/Neovim for testing editor plugins. This tool is useful to install various versions of the editors; stable, nightly, specific version for every platform (Linux, Windows, macOS) which GitHub Actions supports.

This action is already used by many uses. Here is the search result on GitHub: https://github.com/search?l=YAML&q=%22rhysd%2Faction-setup-vim%22&type=Code