neoclide/coc.nvim ? reverse-engineered prompt

Build me a plugin for Vim and Neovim that makes editing feel much smarter, kind of like VS Code.

I want it to connect to language servers through a Node.js process, so I can get autocomplete, diagnostics, go to definition, hover help, rename, and basic refactoring while I type. It should work in both Vim and Neovim, and feel easy to set up with a simple install and a few config options. Please make it support loading extra extensions too, so it can grow over time with more language features. If there are current best practices or docs I should follow, look them up online and use them.

Make the user experience smooth, with sensible defaults, good performance, and clear messages when something is not configured right. Also include a browser friendly demo or at least a clean way to test it locally, plus simple documentation for setup, common commands, and troubleshooting.