message: use social icons in footer
diff: <div class="cardstack-footer__horizontal-stack">
  <a href="https://twitter.com/cardstack" target="_blank" rel="noopener noreferrer" >
  <span class="boxel-sr-only">Cardstack Twitter</span>
  - {{!-- {{svg-jar "twitter" class="cardstack-footer__social-icon"}} --}}
  - {{svg-jar "user" class="cardstack-footer__social-icon"}}
  + {{svg-jar "twitter-logo" class="cardstack-footer__social-icon"}}
  </a>
  <a href="https://telegram.me/cardstack" target="_blank" rel="noopener noreferrer" >
  <span class="boxel-sr-only">Cardstack Telegram</span>
  - {{!-- {{svg-jar "telegram" class="cardstack-footer__social-icon"}} --}}
  - {{svg-jar "user" class="cardstack-footer__social-icon"}}
  + {{svg-jar "telegram-logo" class="cardstack-footer__social-icon"}}
  </a>
  <a href="https://github.com/cardstack/cardstack" target="_blank" rel="noopener noreferrer" >
  <span class="boxel-sr-only">Cardstack Monorepo</span>
  - {{!-- {{svg-jar "github" class="cardstack-footer__social-icon"}} --}}
  - {{svg-jar "user" class="cardstack-footer__social-icon"}}
  + {{svg-jar "github-logo" class="cardstack-footer__social-icon"}}
  </a>
  <a href="https://medium.com/cardstack" target="_blank" rel="noopener noreferrer" >
  <span class="boxel-sr-only">Cardstack Medium</span>
  - {{!-- {{svg-jar "medium" class="cardstack-footer__social-icon"}} --}}
  - {{svg-jar "user" class="cardstack-footer__social-icon"}}
  + {{svg-jar "medium-logo" class="cardstack-footer__social-icon"}}
  </a>
  </div>
  </div>
  