Fix wrapping of assignments anchors

app/views/assignments/index.html.erb

@@ -3,7 +3,7 @@
   <h1 class="text-xl my-4">Assignments for all users</h1>
   <p>
     Jump to:
-    <ul class="flex flex-row">
+    <ul class="flex flex-row flex-wrap">
     <% @assignments.group_by(&:user).each_with_index do |(user, assignments), index| %>
       <li>
         <%= link_to user.name, "#" + dom_id(user), class: index == 0 ? "" : "border-l-2 border-gray-300 pl-2 ml-2" %>