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/image_captions.ipynb

@@ -6,9 +6,23 @@
    "metadata": {},
    "source": [
     "# Image captions\n",
+    "\n",
+    "By default, the loader utilizes the pre-trained [Salesforce BLIP image captioning model](https://huggingface.co/Salesforce/blip-image-captioning-base).\n",
+    "\n",
+    "\n",
     "This notebook shows how to use the ImageCaptionLoader tutorial to generate a query-able index of image captions"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "9f78585a-a2fa-4ece-834f-66692b959efb",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#!pip install transformers"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 1,
@@ -232,7 +246,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.1"
+   "version": "3.10.6"
   }
  },
  "nbformat": 4,