message: correct the repo url for the GitHub Stars widget.
diff: <!-- Place this tag where you want the button to render. -->
  <a
  class="github-button"
  - href="https://github.com/ntkme/github-buttons"
  + href="https://github.com/gitpod-io/gitpod"
  data-icon="octicon-star"
  data-size="large"
  data-show-count="true"
  - aria-label="Star ntkme/github-buttons on GitHub">Star</a
  + aria-label="Star the Gitpod Repo on GitHub">Star</a
  >
  </div>
  </div>
  