nix: fix default opts not applying

previously mkDefault/mkOverride on vim.options would go before nvf's
defaults, which would basically make none of them apply. now it doesn't
use an override priority, at the cost that overriding any of these in a
user config will not work without mkForce.

also enable swapfiles, closes #1

modules/neovim/default.nix

@@ -5,6 +5,7 @@
   ...
 }:
 {
+  imports = [ ./options.nix ];
   # based on default options from upstream:
   # https://github.com/NotAShelf/nvf/blob/main/configuration.nix
   #
@@ -18,23 +19,6 @@
       enable = true;
     };
 
-    options = {
-      tabstop = 2;
-      softtabstop = 2;
-      shiftwidth = 2;
-      undofile = true;
-      swapfile = false;
-      showmode = false;
-      foldlevel = 99;
-      foldcolumn = "1";
-      foldlevelstart = 99;
-      foldenable = true;
-      foldmethod = "expr";
-      #Default to treesitter folding
-      foldexpr = "v:lua.vim.treesitter.foldexpr()";
-    };
-
-
     visuals = {
       # notification system
       # https://github.com/j-hui/fidget.nvim
@@ -110,7 +94,6 @@
       css.enable = true;
       html.enable = true;
       markdown.enable = true;
-      nix.enable = true;
       python.enable = true;
       rust.crates.enable = true;
       rust.enable = true;
@@ -120,7 +103,11 @@
       # sort-lines: off
 
       ts.format.enable = false; # deno fmt is enabled elsewhere
-      nix.format.type = "nixfmt"; # looks so much nicer
+      nix = {
+        enable = true;
+        format.type = "nixfmt"; # looks so much nicer
+        lsp.options.autoArchive = true;
+      };
     };
     formatter.conform-nvim = {
       enable = true;

modules/neovim/options.nix

@@ -0,0 +1,26 @@
+{ ... }:
+{
+  config.vim.options = {
+    # Indentation
+    tabstop = 2;
+    softtabstop = 2;
+    shiftwidth = 2;
+    showmode = false;
+
+    # Default to treesitter folding
+    foldenable = true;
+    foldmethod = "expr";
+    foldexpr = "v:lua.vim.treesitter.foldexpr()";
+    foldlevel = 99;
+    foldcolumn = "1";
+    foldlevelstart = 99;
+
+    # Case-insensitive find-in-file
+    ignorecase = true;
+    smartcase = true;
+
+    # Enable swapfile, but not in the same location as the source files.
+    undofile = true;
+    swapfile = true;
+  };
+}