docs: introduce docs site (#141)

Signed-off-by: Panos Vagenas <35837085+vagenas@users.noreply.github.com>

docs/overrides/main.html

@@ -0,0 +1,7 @@
+{% extends "base.html" %}
+
+{#
+{% block announce %}
+  <p>🎉 Docling is now officially supported in LlamaIndex! <a href="{{ 'integrations/llamaindex/' | url }}">Check it out</a>!</p>
+{% endblock %}
+#}