Treesitter based syntax highlighting and language server client for Neovim.

This requires neovim >= 0.9 and nvim-lspconfig to be installed.

1. Run bazel build //toolchain in project root.
2. Run utils/nvim/setup.sh.
3. Start nvim in carbon-lang root folder and open a carbon file.
4. View document symbols. If you have telescope.nvim installed, you can use :Telescope lsp_document_symbols