Add add user functionality

admin.html

@@ -30,6 +30,12 @@
     .plusbutton {
         width: 3rem;
     }
+
+    .adduser {
+      display: flex;
+      justify-content: flex-end;
+      margin-top: 1rem;
+    }
   </style>
 
 </head>
@@ -64,6 +70,13 @@
     </template>
   </table>
 
+  <div class="adduser">
+    <span>
+      <input type="text" id="newusername" placeholder="Elrond McBong">
+      <input type="button" id="newuserbutton" value="Add">
+    </span>
+  </div>
+
     <script src="../../static/js/admin.js"></script>
 </body>