assistant: add avante.nvim plugin

modules/plugins/assistant/avante/config.nix

@@ -0,0 +1,44 @@
+{
+  pkgs,
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib.modules) mkIf;
+
+  cfg = config.vim.assistant.avante-nvim;
+in {
+  config = mkIf cfg.enable {
+    vim = {
+      startPlugins = [
+        "plenary-nvim"
+        "dressing-nvim"
+        "nui-nvim"
+      ];
+
+      lazy.plugins = {
+        "avante.nvim" = with pkgs.vimPlugins; {
+          package = avante-nvim;
+          setupModule = "avante";
+          inherit (cfg) setupOpts;
+          after =
+            /*
+            lua
+            */
+            ''
+              vim.opt.laststatus = 3
+            '';
+        };
+      };
+
+      treesitter.enable = true;
+
+      autocomplete.nvim-cmp = {
+        sources = {"avante.nvim" = "[avante]";};
+        sourcePlugins = ["avante-nvim"];
+      };
+
+      languages.markdown.extensions.render-markdown-nvim.setupOpts.file_types = lib.mkAfter ["Avante"];
+    };
+  };
+}