Does not gracefully handle nested links

[inf3rnus]

Grab the .md from here: https://raw.githubusercontent.com/daohu527/awesome-self-driving-car/master/README.md

The component will throw an error to console: Warning: validateDOMNesting(...): <a> cannot appear as a descendant of <a>.

Not sure what's required to fix it, but you have the info :)

[inf3rnus]

Note, if anyone else gets this issue, it can be fixed externally via:

const hasNestedAnchors = (element, depth = 0) => {
  const { tagName, children } = element;

  if (children === undefined || (tagName !== "a" && depth === 0)) {
    return false;
  }

  if (depth > 0 && tagName === "a") {
    return true;
  } else {
    for (const child of children) {
      if (hasNestedAnchors(child, depth + 1)) {
        return true;
      }
    }
    return false;
  }
};

and then pass that into MarkdownPreview like so:

<MarkdownPreview allowElement={element => !hasNestedAnchors(element)} />