feat(site): add contact page and enterprise link on landing page (#15)

Author: raphaelmansuy

site/src/components/SocialIcons.astro

@@ -11,6 +11,7 @@
     <a href="/guides/rag-integration/" class="nav-link">Guides</a>
     <a href="/benchmark/results/" class="nav-link">Benchmark</a>
     <a href="/enterprise/" class="nav-link">Enterprise</a>
+    <a href="/contact/" class="nav-link">Contact</a>
     <a href="/demo/" class="nav-link nav-link--demo">Demo</a>
   </nav>
   <div class="social-actions">