Make use of jekyll-toc's no_toc_section class.

Requires jekyll-toc v0.8.0.

site/_includes/callout.html

@@ -4,6 +4,6 @@ where content is a capture with the content
 and type is one of: info (default), danger, warning
 {%- endcomment -%}
 {%- assign css_class = include.type | default: "info" -%}
-<div class="bd-callout bd-callout-{{ css_class }}">
+<div class="bd-callout bd-callout-{{ css_class }} no_toc_section">
   {{- include.content | markdownify -}}
 </div>

site/_includes/example.html

@@ -11,7 +11,7 @@ optional: hide_markup - disabled (default)
 {%- assign preview_class = include.class -%}
 
 {%- if include.hide_preview == null -%}
-<div{% if preview_id %} id="{{ preview_id }}"{% endif %} class="bd-example{% if preview_class %} {{ preview_class }}{% endif %}">
+<div{% if preview_id %} id="{{ preview_id }}"{% endif %} class="bd-example no_toc_section{% if preview_class %} {{ preview_class }}{% endif %}">
   {{- include.content -}}
 </div>
 {%- endif -%}

site/docs/4.1/assets/scss/_sidebar.scss

@@ -23,10 +23,6 @@
 
   ul {
     padding-left: 1rem;
-
-    ul {
-      display: none;
-    }
   }
 }