Improve rendering of TOC items

The table of contents now support headings generated by shortcodes. Be sure to include an `id` if your custom partials or shortcodes include HTML headings (h1-h6). To exclude these headings from the TOC, use the attribute `fs-` to define a font size.

exampleSite/hugo_stats.json

@@ -14,7 +14,6 @@
       "footer",
       "form",
       "h2",
-      "h3",
       "head",
       "hr",
       "html",
@@ -252,6 +251,7 @@
       "font-monospace",
       "footer",
       "form-control",
+      "fs-2",
       "fs-3",
       "fs-5",
       "fs-6",
@@ -357,7 +357,6 @@
       "p-2",
       "p-3",
       "p-4",
-      "pb-2",
       "pb-3",
       "pb-4",
       "pb-5",
@@ -373,6 +372,7 @@
       "ps-1",
       "ps-3",
       "pt-1",
+      "pt-4",
       "pt-5",
       "pt-md-3",
       "ptw-3",
@@ -469,6 +469,8 @@
       "toast-header",
       "toc",
       "toc-button",
+      "toc-item",
+      "toc-level-1",
       "toc-panel",
       "toc-sidebar",
       "toggler-icon",
@@ -485,7 +487,6 @@
       "w-50"
     ],
     "ids": [
-      "TableOfContents",
       "abbr",
       "accordion",
       "accordion-0",