Add an nvim package

Now I can run `nix run .#nvim` to run Neovim with any configuration
changes without having to rebuild my whole NixOS configuration.

flake.nix

@@ -42,6 +42,12 @@
       };
 
       inherit (pkgs) mkShell;
+
+      neovimWithConfig = inputs.nixvim.legacyPackages.${system}.makeNixvimWithModule {
+        inherit pkgs;
+
+        module = import ./modules/home-manager/coding/neovim/nixvim.nix;
+      };
     in
     {
       devShells.${system}.default = pkgs.mkShell {
@@ -55,6 +61,8 @@
 
       packages.${system} = {
         default = mkShell { buildInputs = with pkgs; [ just ]; };
+
+        nvim = neovimWithConfig;
       };
 
       formatter.${system} = pkgs.nixfmt-rfc-style;

modules/home-manager/coding/neovim/default.nix

@@ -2,7 +2,6 @@
   config,
   inputs,
   lib,
-  pkgs,
   ...
 }:
 
@@ -22,67 +21,10 @@ in
     programs.nixvim = {
       enable = true;
 
-      # TODO: re-add DAP.
-      # TODO: re-add snippets.
-      # TODO: re-configure spell.
-
       viAlias = true;
       vimAlias = true;
 
-      imports = [
+      imports = [ ./nixvim.nix ];
-        ./keymaps.nix
-        ./options.nix
-        ./plugins/cmp.nix
-        ./plugins/conform.nix
-        ./plugins/fidget.nix
-        ./plugins/fugitive.nix
-        ./plugins/gitsigns.nix
-        ./plugins/harpoon.nix
-        ./plugins/lint.nix
-        ./plugins/lsp.nix
-        ./plugins/lualine.nix
-        ./plugins/luasnip.nix
-        ./plugins/mini.nix
-        ./plugins/nvim-autopairs.nix
-        ./plugins/oil.nix
-        ./plugins/phpactor.nix
-        ./plugins/refactoring.nix
-        ./plugins/telescope.nix
-        ./plugins/treesitter.nix
-        ./plugins/undotree.nix
-        ./plugins/vim-dadbod.nix
-        ./plugins/vim-highlightedyank.nix
-        ./plugins/vim-test.nix
-        ./plugins/web-devicons.nix
-      ];
-
-      colorschemes.catppuccin = {
-        enable = true;
-        settings.flavour = "mocha";
-      };
-
-      extraPackages = with pkgs; [
-        nixfmt-rfc-style
-        stylua
-      ];
-
-      filetype = {
-        extension = {
-          "neon.dist" = "yaml";
-          inc = "php";
-          install = "php";
-          module = "php";
-          neon = "yaml";
-          pcss = "scss";
-          theme = "php";
-        };
-
-        filename = {
-          "composer.lock" = "json";
-        };
-      };
-
-      globals.mapleader = " ";
     };
   };
 }

modules/home-manager/coding/neovim/nixvim.nix

@@ -0,0 +1,62 @@
+{ pkgs, ... }:
+
+{
+  # TODO: re-add DAP.
+  # TODO: re-add snippets.
+  # TODO: re-configure spell.
+
+  imports = [
+    ./keymaps.nix
+    ./options.nix
+    ./plugins/cmp.nix
+    ./plugins/conform.nix
+    ./plugins/fidget.nix
+    ./plugins/fugitive.nix
+    ./plugins/gitsigns.nix
+    ./plugins/harpoon.nix
+    ./plugins/lint.nix
+    ./plugins/lsp.nix
+    ./plugins/lualine.nix
+    ./plugins/luasnip.nix
+    ./plugins/mini.nix
+    ./plugins/nvim-autopairs.nix
+    ./plugins/oil.nix
+    ./plugins/phpactor.nix
+    ./plugins/refactoring.nix
+    ./plugins/telescope.nix
+    ./plugins/treesitter.nix
+    ./plugins/undotree.nix
+    ./plugins/vim-dadbod.nix
+    ./plugins/vim-highlightedyank.nix
+    ./plugins/vim-test.nix
+    ./plugins/web-devicons.nix
+  ];
+
+  colorschemes.catppuccin = {
+    enable = true;
+    settings.flavour = "mocha";
+  };
+
+  extraPackages = with pkgs; [
+    nixfmt-rfc-style
+    stylua
+  ];
+
+  filetype = {
+    extension = {
+      "neon.dist" = "yaml";
+      inc = "php";
+      install = "php";
+      module = "php";
+      neon = "yaml";
+      pcss = "scss";
+      theme = "php";
+    };
+
+    filename = {
+      "composer.lock" = "json";
+    };
+  };
+
+  globals.mapleader = " ";
+}