old
 1{...}: {
 2  programs.helix.languages = {
 3    language = [
 4      {
 5        name = "html";
 6        auto-format = true;
 7        indent = {
 8          tab-width = 2;
 9          unit = "  ";
10        };
11        language-servers = ["vscode-html-language-server" "tailwindcss-ls"];
12        formatter = {
13          command = "prettier";
14          args = ["--parser" "html" "--stdin-filepath" "%{buffer_name}"];
15        };
16      }
17    ];
18  };
19}