Fix TNL-6139

common/static/common/templates/discussion/inline-discussion.underscore

@@ -13,6 +13,7 @@
             <div class="forum-nav-bar">
                 <button class="btn-link all-posts-btn">
                     <span class="icon fa fa-chevron-prev" aria-hidden="true"></span>
+                    <span class="sr-only"><%- gettext('Return to') %></span>
                     <span><%- gettext('All Posts') %></span>
                 </button>
             </div>