Add README and sync mason_ensure_installed with NixOS extraPackages

README.md

@@ -0,0 +1,62 @@
+# Neovim Configuration
+
+Portable Neovim configuration using lazy.nvim and native LSP (Neovim 0.11+).
+
+## Installation
+
+### Standalone (any system)
+```bash
+git clone git@github.com:itme-brain/nvim.git ~/.config/nvim
+```
+
+### As part of NixOS config
+```bash
+git clone --recurse-submodules git@github.com:itme-brain/nixos.git
+```
+
+## Features
+
+- **Native LSP** (`vim.lsp.config`) - no manual server list needed
+- **Smart LSP picker** (`<leader>css`) - auto-detects installed servers for current filetype
+- **Portable** - works on NixOS (LSPs via extraPackages) or any system (LSPs via Mason)
+- **Mason** - auto-disabled on NixOS, auto-installs essentials elsewhere
+
+## LSP Setup
+
+On NixOS, LSPs come from:
+- `neovim.extraPackages` (global essentials)
+- Project `devShell` (project-specific)
+
+On other systems, Mason installs: `lua_ls`, `bashls`, `jsonls`
+
+The smart picker (`<leader>css`) scans all lspconfig servers and shows only those with binaries installed.
+
+## Key Bindings
+
+| Key | Action |
+|-----|--------|
+| `<leader>css` | Start LSP (smart picker) |
+| `<leader>csx` | Stop LSP |
+| `<leader>csr` | Restart LSP |
+| `<leader>cf` | Format code |
+| `<leader>ca` | Code action |
+| `<leader>cr` | Rename symbol |
+| `gd` | Go to definition |
+| `<leader>gr` | Find references |
+| `<leader>e` | Toggle file explorer |
+| `<leader>bd` | Delete buffer |
+| `<leader>/` | Live grep |
+| `<leader>ff` | Find files |
+
+## Plugins
+
+- **lazy.nvim** - plugin manager
+- **nvim-lspconfig** - LSP configurations
+- **nvim-cmp** - completion
+- **telescope.nvim** - fuzzy finder
+- **nvim-treesitter** - syntax highlighting
+- **neo-tree.nvim** - file explorer
+- **gitsigns.nvim** - git integration
+- **lualine.nvim** - statusline
+- **bufferline.nvim** - buffer tabs
+- **which-key.nvim** - keybinding hints

lua/plugins/lsp.lua

@@ -8,9 +8,14 @@ local is_nixos = vim.fn.filereadable("/etc/NIXOS") == 1
 -- On NixOS, install these via extraPackages or per-project devShells
 local mason_ensure_installed = {
   "lua_ls",       -- Neovim config
-  "nil_ls",       -- Nix
+  "nil_ls",       -- Nix (nixd not available in Mason)
   "bashls",       -- Shell scripts
   "jsonls",       -- JSON configs
+  "html",         -- HTML
+  "cssls",        -- CSS
+  "marksman",     -- Markdown
+  "taplo",        -- TOML
+  "yamlls",       -- YAML
 }
 
 return {