message: add the missing links.
diff: Tweak your environment to suit your needs. From themes to extensions you
  have full control over it all.
  </p>
  - <a href="/docs/config-docker">More about customization</a>
  + <a href="/docs/vscode-extensions/">More about customization</a>
  </div>
  <div class="card">
  <!-- TODO: Insert icon -->
  in a ready-to-code dev environment.
  </p>
  <!-- TODO: Figure out where to link to: -->
  - <a href="TODO:">More about Integrations</a>
  + <a href="/docs/integrations/">More about Integrations</a>
  </div>
  <div class="card">
  <!-- TODO: Insert icon -->
  