DOCS: Automatically make a table of contents (TOC) (#1778)

docs/_includes/table-of-contents.md

@@ -0,0 +1,28 @@
+<a href="#{{include.html-anchor}}">
+    <strong>{{include.title}}</strong>
+</a>
+{% if include.provider-jsId != nill %}
+    for
+    <a href="/providers/{{include.provider-jsId}}">
+        <strong>
+            {{include.provider-name}}
+        </strong>
+    </a>
+{% endif %}
+
+<ul>
+{% for function in site.functions %}
+    {% if function.path contains include.docs-functions-dir %}
+        {% if include.docs-functions-dir == "domain" %}
+            {% if include.provider-jsId == nill and function.provider == nill %}
+                <li><a href="#{{function.name}}">{{function.name}}</a></li>
+            {% endif %}
+            {% if include.provider-jsId != nill and function.provider == include.provider-jsId %}
+                <li><a href="#{{function.name}}">{{function.name}}</a></li>
+            {% endif %}
+        {% else %}
+            <li><a href="#{{function.name}}">{{function.name}}</a></li>
+        {% endif %}
+    {% endif %}
+{% endfor %}
+</ul>