chore: simplify templates

[Rich-Harris]

This simplifies the template logic — fewer function calls, and shorter compiled output (particularly when mixing and matching fragments and elements etc)

-var frag = $.template(`<button> </button>`);
+var root = $.template(`<button> </button>`);

export default function App($$anchor, $$props) {
  $.push($$props, true);

  let count = $.source(0);
-  var button = $.open(frag);
+  var button = root();

  button.__click = [increment, count];

  var text = $.child(button);

  $.render_effect(() => $.set_text(text, `clicks: ${$.stringify($.get(count))}`));
-  $.close($$anchor, button);
+  $.append($$anchor, button);
  $.pop();
}

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• Ideally, include a test that fails without this PR but passes with it.

Tests and linting

• Run the tests with pnpm test and lint the project with pnpm lint

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Latest commit: 93fd685

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