sort user assignments list view

app/views/assignments/by_user.html.erb

@@ -7,7 +7,7 @@
   <% now = Time.now %>
   <div>
     <h2 class="text-lg my-4">List View</h2>
-    <% @user.assignments.group_by { |a| a.session.starts_at.strftime('%Y-%m-%d') }.each do |date, assignments_on_date| %>
+    <% @user.assignments.includes(:session, session: :conference).order('sessions.starts_at').group_by { |a| a.session.starts_at.strftime('%Y-%m-%d') }.each do |date, assignments_on_date| %>
       <h5 class="text-base mt-2 <%= date < now ? "past" : "future" %>"><%= date %></h5>
       <ol class="list-inside">
         <% assignments_on_date.each do |assignment| %>