added svg file

_index.html

@@ -110,7 +110,7 @@ <h4>Join the Community</h4>
 			</div>
 			<div class="col-sm-12 col-md-4 col-lg-3 text-center">
 				<div class="mb-4 h1">
-					<i class="fa-brands fa-x-twitter"></i>
+					<svg xmlns="http://www.w3.org/2000/svg" height="1em" viewBox="0 0 512 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license (Commercial License) Copyright 2023 Fonticons, Inc. --><path d="M389.2 48h70.6L305.6 224.2 487 464H345L233.7 318.6 106.5 464H35.8L200.7 275.5 26.8 48H172.4L272.9 180.9 389.2 48zM364.4 421.8h39.1L151.1 88h-42L364.4 421.8z"/></svg>
 				</div>
 				<h4>Follow us on Twitter</h4>
 				<p><a href="https://twitter.com/KnativeProject">

mkdocs.yml

@@ -68,7 +68,10 @@ copyright: "Copyright © 2022 The Knative Authors"
 
 extra:
   social:
-    - icon: fontawesome/brands/x-twitter
+    - icon: |
+        <svg xmlns="http://www.w3.org/2000/svg" height="1em" viewBox="0 0 512 512">
+          <path d="M389.2 48h70.6L305.6 224.2 487 464H345L233.7 318.6 106.5 464H35.8L200.7 275.5 26.8 48H172.4L272.9 180.9 389.2 48zM364.4 421.8h39.1L151.1 88h-42L364.4 421.8z"/>
+        </svg>
       link: https://twitter.com/KnativeProject
     - icon: fontawesome/brands/github
       link: https://github.com/knative/community