ui: hide delete-account behind a header hamburger menu

static/index.html

@@ -14,7 +14,12 @@
   </form>
   <span id="me" class="muted"></span>
   <button id="logout" class="tiny" style="display:none">logout</button>
-  <button id="delacct" class="tiny danger" style="display:none">delete</button>
+  <div id="menubox" style="display:none">
+    <button id="menu" class="tiny" aria-label="menu" aria-haspopup="true">☰</button>
+    <div id="menu-items">
+      <button id="delacct" class="tiny danger">delete account</button>
+    </div>
+  </div>
 </header>
 <main id="main"><p class="muted">Search for an anime to get started.</p></main>
 <script src="hls.min.js"></script>