Combine local JS.

’yui-compressor’ is no longer used.

assets/js/_utils/toc.js

@@ -0,0 +1,14 @@
+/*
+ * Hide the empty ToC in posts.
+ * v2.0
+ * https://github.com/cotes2020/jekyll-theme-chirpy
+ * © 2019 Cotes Chung
+ * MIT Licensed
+ */
+
+$(function() {
+  if ($("#post-wrapper .post-content h1").length == 0
+      && $("#post-wrapper .post-content h2").length == 0) {
+    $("#toc-wrapper").addClass("unloaded");
+  }
+});