[PYT-642] update blurb & link added on mobile menu

Author: arielmoguillansky

_includes/mobile_menu.html

@@ -37,6 +37,9 @@
           <li>
             <a href="{{ site.baseurl }}/ecosystem/pted/2021">Ecosystem Day 2021</a>
           </li>
+          <li>
+            <a href="{{ site.baseurl }}/ecosystem/ptdd/2021">Developer's Day 2021</a>
+          </li>
         </ul>
 
         <li class="{% if current[1] == 'mobile' %}active{% endif %}">

ecosystem/ptdd/2021.html

@@ -17,16 +17,18 @@ <h1 class="lead">2021</h1>
   <div class="main-content">
     <div class="container">
       <p class="lead">
-        Thank you to the incredible PyTorch Community for making the first ever
-        PyTorch Ecosystem Day a success! Ecosystem Day was hosted on Gather.Town
-        utilizing an auditorium, exhibition hall, and breakout rooms for
-        partners to reserve for talks, demos, or tutorials. In order to cater to
-        the global community, the event held two sessions: a morning session
-        from 8am PT - 1pm PT and an evening session from 3:00pm -7:00pm PT. The
-        day was filled with discussions on new developments, trends and
-        challenges showcased through 71 posters, 32 breakout sessions and 6
-        keynote speakers.
+        PYTORCH DEVELOPER DAY: DAY 2 INFORMATION
       </p>
+      <p class="lead">
+        Community Talks:
+      </p>
+      <ul class="lead">
+        <li>
+          <a href="https://www.youtube.com/watch?v=7yQ4FgtYvj8"
+            >PyTorch YouTube</a
+          >
+        </li>
+      </ul>
       <div class="input-group mb-3">
         <input
           type="text"