nixpkgs/neovim: use html-tidy in kulala

.config/nixpkgs/neovim/config/lua/user/rest.lua

@@ -2,5 +2,10 @@ vim.cmd.packadd('kulala.nvim')
 
 require('kulala').setup({
   global_keymaps = true,
-  global_keymaps_prefix = '<leader>r'
+  global_keymaps_prefix = '<leader>r',
+  contenttypes = {
+    ['text/html'] = {
+      formatter = { 'tidy', '-wrap', '0', '-i', '-q' }
+    }
+  }
 })