Add YouTube logo and link to Slang playlist

Author: allcreatures

_data/social.json

@@ -19,6 +19,11 @@
     "link": "https://bsky.app/profile/shader-slang.bsky.social",
     "image": "images/social/bluesky.svg"
   },
+  {
+    "name": "Youtube",
+    "link": "https://www.youtube.com/playlist?list=PLYO7XTAX41FNNKUBI6BogkPFGwZ6x4-NE",
+    "image": "images/social/youtube.svg"
+  },
   {
     "name": "Reddit",
     "link": "https://www.reddit.com/r/shaderslang/",

_includes/footer.html

@@ -1,7 +1,7 @@
   <div class="container">
     <p class="visually-hidden-focusable">Page footer starts here. <a href="#backtop">Return to main content</a></p>
     <div class="row">
-      <div class="col-xs-12 col-sm-9 footer_branding">
+      <div class="col-xs-12 col-sm-8 footer_branding">
         <figure><a href="https://www.khronos.org/"><img src="/images/khronos-logo.svg"
               alt="Khronos Logo"></a></figure>
         <p>Slang is now under open-governance at Khronos to encourage and enable broad industry collaboration to propel its
@@ -20,7 +20,7 @@
       </div>
 
 
-          <div class="col-xs-12 col-sm-3 footer_details">
+          <div class="col-xs-12 col-sm-4 footer_details">
             <div class="h4">Community</div>
             {% if site.data.social %} {% include social.html %} {% endif %}