Switch nix formatter again to nixfmt-rfc-style

modules/home-manager/nixvim/plugins/default.nix

@@ -2,6 +2,7 @@
   imports = [
     ./cmp.nix
     ./lsp.nix
+    ./fmt.nix
     ./treesitter.nix
     ./lualine.nix
     ./nvim-autopairs.nix

modules/home-manager/nixvim/plugins/fmt.nix

@@ -0,0 +1,53 @@
+{ pkgs, ... }:
+{
+  home.packages = with pkgs; [
+    stylua
+    nixfmt-rfc-style
+  ];
+
+  programs.nixvim = {
+    opts.formatexpr = "v:lua.require'conform'.formatexpr()";
+
+    plugins.conform-nvim = {
+      enable = true;
+      lazyLoad.enable = true;
+      lazyLoad.settings = {
+        event = "BufWritePre";
+        cmd = "ConformInfo";
+        keys = [
+          {
+            __unkeyed-1 = "<leader>f";
+            __unkeyed-2.__raw = ''
+              function() require 'conform'.format { async = true } end
+            '';
+            desc = "Format Buffer";
+          }
+        ];
+      };
+      settings = {
+        default_format_opts.lsp_format = "fallback";
+        format_on_save = ''
+          function(bufnr)
+            local disable_filetypes = { c = true, cpp = true }
+            local lsp_format_opt
+            if disable_filetypes[vim.bo[bufnr].filetype] then
+              lsp_format_opt = 'never'
+            else
+              lsp_format_opt = 'fallback'
+            end
+            return {
+              timeout_ms = 500,
+              lsp_format = lsp_format_opt,
+            }
+          end
+        '';
+
+        formatters_by_ft = {
+          lua = [ "stylua" ];
+          python = [ "black" ];
+          nix = [ "nixfmt" ];
+        };
+      };
+    };
+  };
+}

modules/home-manager/nixvim/plugins/lsp.nix

@@ -23,9 +23,6 @@
           pyright.enable = true;
         };
       };
-      lsp-format = {
-        enable = true;
-      };
     };
   };
 }