nvim-lsp-installerからmason.nvimへ移行する

NeovimのLSPの設定支援プラグインとして人気だったnvim-lsp-installerの開発終了が発表されました。 nvim-lsp-installer will no longer be actively maintained, meaning I won't be doing things like porting new mason.nvim packages to nvim-lsp-installer, monitoring lspconfig for changes that require updates, or put much effort into user support or bug issues (the recommendation for the latter will be to migrate to mason.nvim). 現在、同じ作者の後継プロジ