update: callingの応答ボタンをマークアップ

public/index.html

@@ -242,6 +242,16 @@
           <div></div><div></div><div></div><div></div>
           <div></div><div></div><div></div><div></div>
         </section>
+        <section class="calling__controls-btn">
+          <div class="btn btn-1">
+            <div></div><div></div><div></div><div></div>
+            <i class="fas fa-phone"></i>
+          </div>
+          <div class="btn btn-2">
+            <div></div><div></div><div></div><div></div>
+            <i class="fas fa-phone"></i>
+          </div>
+        </section>
       </section>
     </main>
     <script type="text/javascript" src="./scripts/app.min.js"></script>