Vwp/docs improved document loaders (#4006)

Huge thanks to @leo-gan for improving the document loaders notebooks

---------

Co-authored-by: Leonid Ganeline <leo.gan.57@gmail.com>

docs/modules/indexes/document_loaders/examples/diffbot.ipynb

@@ -1,13 +1,16 @@
 {
  "cells": [
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "2dfc4698",
    "metadata": {},
    "source": [
     "# Diffbot\n",
     "\n",
+    ">Unlike traditional web scraping tools, [Diffbot](https://docs.diffbot.com/docs) doesn't require any rules to read the content on a page.\n",
+    ">It starts with computer vision, which classifies a page into one of 20 possible types. Content is then interpreted by a machine learning model trained to identify the key attributes on a page based on its type.\n",
+    ">The result is a website transformed into clean structured data (like JSON or CSV), ready for your application.\n",
+    "\n",
     "This covers how to extract HTML documents from a list of URLs using the [Diffbot extract API](https://www.diffbot.com/products/extract/), into a document format that we can use downstream."
    ]
   },
@@ -24,7 +27,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "6fffec88",
    "metadata": {},
@@ -45,7 +47,6 @@
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
    "id": "e0ce8c05",
    "metadata": {},