add connect button for ws html5 (#621)

zhaomingwork

2023-06-12 d7e3ae17c3ac056752ecf5c41ff9a96645fcad49

 funasr/runtime/html5/static/index.html

@@ -36,6 +36,7 @@
            <br>

                <div id="info_div">请点击开始</div>

            <div class="div_class_buttons">

               <button id="btnConnect">连接</button>

               <button id="btnStart">开始</button>

               <button id="btnStop">停止</button>