message: Remove dead code in the highlighter
  ... not sure what I was seeing with weird tokens previously, but there is no reason for the partial consumption to be necessary.
diff: import { ok as assert } from "assert";
  import { BUNDLED_LANGUAGES, getHighlighter, Highlighter, Theme } from "shiki";
  -import { unique } from "./array";
  +import { unique, zip } from "./array";
  import * as JSX from "./jsx";
  const aliases = new Map<string, string>();
  @@ -24,49 +24,16 @@ class DoubleHighlighter {
  // If this fails... something went *very* wrong.
  assert(lightTokens.length === darkTokens.length);
  - const docEls: JSX.Element[][] = [];
  + const docEls: JSX.Element[] = [];
  - for (let line = 0; line < lightTokens.length; line++) {
  - const lightLine = lightTokens[line];
  - const darkLine = darkTokens[line];
  + for (const [lightLine, darkLine] of zip(lightTokens, darkTokens)) {
  + // If this fails, something also went *very* wrong.
  + assert(lightLine.length === darkLine.length);
  - // Different themes can have different grammars... so unfortunately we have to deal with different
  - // sets of tokens.Example: light_plus and dark_plus tokenize " = " differently in the `schemes`
  - // declaration for this file.
  -
  - const lineEls: JSX.Element[] = [];
  -
  - while (lightLine.length && darkLine.length) {
  - // Simple case, same token.
  - if (lightLine[0].content === darkLine[0].content) {
  - lineEls.push(
  - <span class={this.getClass(lightLine[0].color, darkLine[0].color)}>{lightLine[0].content}</span>
  - );
  - lightLine.shift();
  - darkLine.shift();
  - continue;
  - }
  -
  - if (lightLine[0].content.length < darkLine[0].content.length) {
  - lineEls.push(
  - <span class={this.getClass(lightLine[0].color, darkLine[0].color)}>{lightLine[0].content}</span>
  - );
  - darkLine[0].content = darkLine[0].content.substr(lightLine[0].content.length);
  - lightLine.shift();
  - continue;
  - }
  -
  - lineEls.push(
  - <span class={this.getClass(lightLine[0].color, darkLine[0].color)}>{darkLine[0].content}</span>
  - );
  - lightLine[0].content = lightLine[0].content.substr(darkLine[0].content.length);
  - darkLine.shift();
  - }
  -
  - if (line + 1 !== lightTokens.length) {
  - lineEls.push(<br />);
  + for (const [lightToken, darkToken] of zip(lightLine, darkLine)) {
  + docEls.push(<span class={this.getClass(lightToken.color, darkToken.color)}>{lightToken.content}</span>);
  }
  - docEls.push(lineEls);
  + docEls.push(<br />);
  }
  return JSX.renderElement(<>{docEls}</>);
  