modules: start breaking down core modules; simplify tree structure

modules/plugins/ui/illuminate/config.nix

@@ -0,0 +1,24 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkIf nvim;
+
+  cfg = config.vim.ui.illuminate;
+in {
+  config = mkIf cfg.enable {
+    vim.startPlugins = ["vim-illuminate"];
+
+    vim.luaConfigRC.vim-illuminate = nvim.dag.entryAnywhere ''
+        require('illuminate').configure({
+          filetypes_denylist = {
+          'dirvish',
+          'fugitive',
+          'NvimTree',
+          'TelescopePrompt',
+        },
+      })
+    '';
+  };
+}

modules/plugins/ui/illuminate/default.nix

@@ -0,0 +1,6 @@
+_: {
+  imports = [
+    ./config.nix
+    ./illuminate.nix
+  ];
+}

modules/plugins/ui/illuminate/illuminate.nix

@@ -0,0 +1,11 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkEnableOption;
+in {
+  options.vim.ui.illuminate = {
+    enable = mkEnableOption "vim-illuminate: automatically highlight other uses of the word under the cursor";
+  };
+}