emacs: Load neovim config from a Lua file

this allows for better editing experience compared to the stringly mess
from before.

So now Emacs is good for modifying NeoVim config, with support for both
Nix and Lua, and NeoVim is capable of editing Emacs config via orgmode.
Nice :)

hosts/bebop/home.nix

@@ -1,7 +1,8 @@
-{ config, pkgs, ... }:
+{ ... }:
 
 {
   imports = [
     ../../modules/common-home.nix
+    ../../modules/neovim/nvim.nix
   ];
 }

hosts/hermes/doom/config.org

@@ -1162,7 +1162,7 @@ When Emacs is opened in Windows Subsystem for Linux, open web links in Firefox o
 ** Lua
 #+begin_src emacs-lisp :lexical t
 (use-package! lua-mode
-  :config
+  :init
   (setq! lua-indent-close-paren-align nil
          lua-indent-level 4
          lua-indent-nested-block-content-align t))

hosts/hermes/home.nix

@@ -3,6 +3,7 @@
 {
   imports = [
     ../../modules/common-home.nix
+    ../../modules/neovim/nvim.nix
 
     ./mail.nix
     ./emacs.nix

modules/common-home.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ config, ... }:
 
 {
   home.stateVersion = "22.05";
@@ -78,52 +78,6 @@
       enableFishIntegration = true;
     };
 
-    neovim = {
-      enable = true;
-      vimAlias = true;
-      withPython3 = false;
-      withRuby = false;
-      withNodeJs = false;
-      plugins = with pkgs.vimPlugins; [
-        nvim-treesitter.withAllGrammars
-        neogit
-        orgmode
-        lualine-nvim
-      ];
-      extraConfig = ''
-        set nobackup
-        set number
-        set relativenumber
-      '';
-      extraLuaConfig = ''
-        -- Neogit (magit clone)
-        local neogit = require('neogit')
-        neogit.setup {}
-
-        -- Lualine
-        require('lualine').setup()
-
-        -- Load custom treesitter grammar for org filetype
-        require('orgmode').setup_ts_grammar()
-
-        -- Treesitter configuration
-        require('nvim-treesitter.configs').setup {
-             -- If TS highlights are not enabled at all, or disabled via `disable` prop,
-             -- highlighting will fallback to default Vim syntax highlighting
-             highlight = {
-                enable = true,
-                -- Required for spellcheck, some LaTex highlights and
-                -- code block highlights that do not have ts grammar
-                additional_vim_regex_highlighting = {'org'},
-             },
-        }
-
-        require('orgmode').setup({
-          org_agenda_files = {'~/org/**/*'},
-        })
-      '';
-    };
-
     htop = {
       enable = true;
       settings = {

modules/neovim/init.lua

@@ -0,0 +1,32 @@
+-- Vim/NeoVim built-ins
+vim.o.nobackup = true
+vim.o.number = true
+vim.o.relativenumber = true
+
+-- Neogit (magit clone)
+require('neogit').setup()
+
+-- Lualine
+require('lualine').setup()
+
+-- Load custom treesitter grammar for org filetype
+require('orgmode').setup_ts_grammar()
+
+-- Treesitter configuration
+require('nvim-treesitter.configs').setup {
+    -- If TS highlights are not enabled at all, or disabled via `disable` prop,
+    -- highlighting will fallback to default Vim syntax highlighting
+    highlight = {
+        enable = true,
+        -- Required for spellcheck, some LaTex highlights and
+        -- code block highlights that do not have ts grammar
+        additional_vim_regex_highlighting = {'org'},
+    },
+}
+
+-- Orgmode
+require('orgmode').setup({
+        org_agenda_files = {
+            '~/org/**/*'
+        },
+})

modules/neovim/nvim.nix

@@ -0,0 +1,24 @@
+{ pkgs, ... }:
+{
+  xdg.configFile = {
+    "nvim/init.lua" = {
+      source = ./init.lua;
+    };
+  };
+
+  programs = {
+    neovim = {
+      enable = true;
+      vimAlias = true;
+      withPython3 = false;
+      withRuby = false;
+      withNodeJs = false;
+      plugins = with pkgs.vimPlugins; [
+        nvim-treesitter.withAllGrammars
+        neogit
+        orgmode
+        lualine-nvim
+      ];
+    };
+  };
+}

modules/root-home.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ ... }:
 
 {
   imports = [