wip(js): add head.html and assets/js

assets/js/modules/components/toc.js

@@ -0,0 +1,36 @@
+import { TocMobile as mobile } from './toc/toc-mobile';
+import { TocDesktop as desktop } from './toc/toc-desktop';
+
+const desktopMode = matchMedia('(min-width: 1200px)');
+
+function refresh(e) {
+  if (e.matches) {
+    if (mobile.popupOpened) {
+      mobile.hidePopup();
+    }
+
+    desktop.refresh();
+  } else {
+    mobile.refresh();
+  }
+}
+
+function init() {
+  if (document.querySelector('main>article[data-toc="true"]') === null) {
+    return;
+  }
+
+  // Avoid create multiple instances of Tocbot. Ref: <https://github.com/tscanlin/tocbot/issues/203>
+  if (desktopMode.matches) {
+    desktop.init();
+  } else {
+    mobile.init();
+  }
+
+  const $tocWrapper = document.getElementById('toc-wrapper');
+  $tocWrapper.classList.remove('invisible');
+
+  desktopMode.onchange = refresh;
+}
+
+export { init as initToc };