Move Nix files into a nix directory

Move everything from `config` to the root level.

nix/modules/home-manager/neovim.nix

@@ -0,0 +1,202 @@
+{ inputs, pkgs, ... }:
+
+{
+  programs.neovim = {
+    enable = true;
+
+    plugins = with pkgs.vimPlugins; [
+      comment-nvim
+      dial-nvim
+      fidget-nvim
+      gitsigns-nvim
+      harpoon
+      impatient-nvim
+      mini-nvim
+      neodev-nvim
+      nvim-spectre
+      nvim-web-devicons
+      oil-nvim
+      refactoring-nvim
+      sort-nvim
+      treesj
+      undotree
+      vim-abolish
+      vim-eunuch
+      vim-highlightedyank
+      vim-just
+      vim-nix
+      vim-obsession
+      vim-pasta
+      vim-repeat
+      vim-sleuth
+      vim-sort-motion
+      vim-terraform
+      vim-textobj-user
+      vim-unimpaired
+
+      conf-vim
+      edit-alternate-vim
+      nvim-tmux-navigation
+      standard-vim
+      vim-autoread
+      vim-textobj-indent
+      vim-textobj-xmlattr
+      vim-zoom
+
+      # Testing
+      vim-test
+
+      # Git
+      committia-vim
+      diffview-nvim
+      vim-fugitive
+
+      # Debugging
+      nvim-dap
+      nvim-dap-ui
+      nvim-dap-virtual-text
+
+      # Treesitter
+      (pkgs.vimPlugins.nvim-treesitter.withPlugins (
+        plugins: with plugins; [
+          bash
+          comment
+          css
+          csv
+          dockerfile
+          gitattributes
+          gitignore
+          go
+          html
+          javascript
+          json
+          kdl
+          lua
+          luadoc
+          make
+          markdown
+          markdown_inline
+          nix
+          php
+          phpdoc
+          query
+          rst
+          scss
+          sql
+          terraform
+          twig
+          typescript
+          vim
+          vimdoc
+          vue
+          xml
+          yaml
+        ]
+      ))
+      nvim-treesitter-context
+      nvim-treesitter-textobjects
+
+      # LSP, linting and formatting
+      conform-nvim
+      lsp-status-nvim
+      nvim-lint
+      nvim-lspconfig
+
+      # Completion
+      cmp-buffer
+      cmp-calc
+      cmp-cmdline
+      cmp-nvim-lsp
+      cmp-path
+      cmp-treesitter
+      cmp_luasnip
+      lspkind-nvim
+      nvim-cmp
+
+      # Snippets
+      friendly-snippets
+      luasnip
+
+      # Telescope
+      plenary-nvim
+      popup-nvim
+      telescope-frecency-nvim
+      telescope-fzf-native-nvim
+      telescope-live-grep-args-nvim
+      telescope-nvim
+      telescope-ui-select-nvim
+
+      # Databases
+      vim-dadbod
+      vim-dadbod-ui
+      vim-dadbod-completion
+
+      # Themes
+      catppuccin-nvim
+
+      # Configuration.
+      inputs.self.packages.${pkgs.system}.opdavies-nvim
+    ];
+
+    extraLuaConfig = ''
+      if vim.loader then
+        vim.loader.enable()
+      end
+
+      require "opdavies"
+    '';
+
+    extraPackages = with pkgs; [
+      # Languages
+      nodePackages.typescript
+      nodejs-slim
+      php81
+
+      # Language servers
+      gopls
+      lua-language-server
+      lua54Packages.luacheck
+      marksman
+      nixd
+      nodePackages."@tailwindcss/language-server"
+      nodePackages.bash-language-server
+      nodePackages.dockerfile-language-server-nodejs
+      nodePackages.intelephense
+      nodePackages.typescript-language-server
+      nodePackages.vls
+      nodePackages.vscode-langservers-extracted
+      nodePackages.vue-language-server
+      nodePackages.yaml-language-server
+      phpactor
+      terraform-ls
+
+      # Formatters
+      black
+      eslint_d
+      nixfmt-rfc-style
+      nodePackages.prettier
+      stylua
+      yamlfmt
+
+      # Tools
+      hadolint
+      html-tidy
+      nodePackages.jsonlint
+      nodePackages.markdownlint-cli
+      php82Packages.php-codesniffer
+      php82Packages.phpstan
+      proselint
+      shellcheck
+      yamllint
+    ];
+  };
+
+  home.file.".markdownlint.yaml".text = ''
+    default: true
+
+    line-length: false
+
+    no-duplicate-heading:
+      siblings_only: true
+  '';
+}