nvim: lsp: Enable code lens support

Relevant PR
https://github.com/neovim/neovim/pull/13165

nvim/.config/nvim/lua/lsp.lua

@@ -89,6 +89,11 @@ local on_attach = function(client, bufnr)
     vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gq', '<cmd>lua vim.lsp.buf.formatting()<CR>', opts)
   end
 
+  if client.resolved_capabilities.code_lens then
+    vim.api.nvim_buf_set_keymap(bufnr, "n", "gl", "<cmd>lua vim.lsp.codelens.run()<CR>", opts)
+    vim.api.nvim_command [[autocmd CursorHold,CursorHoldI,InsertLeave <buffer> lua vim.lsp.codelens.refresh()]]
+  end
+
   protocol.CompletionItemKind = {
     ' '; -- text
     ' '; -- method