Configuration is required to make coc.nvim easier to work with, since it doesn't change your key-mappings or Vim options. This is done as much as possible to avoid conflict with your other plugins. Some Vim plugins could change key mappings. Please use commands like verbose imap <tab> to make sure that your keymap has taken effect. Different plug-ins of VSCode provide many configuration items, most of which are used by the server, but some are used by the client. If you do not use plug-ins, you...