Unstructured example notebook: add a pdf, related deps (#1011)

Updates the Unstructured example notebook with a PDF example. Includes
additional dependencies for PDF processing (and images, etc).

docs/modules/document_loaders/examples/unstructured_file.ipynb

@@ -17,7 +17,9 @@
    "outputs": [],
    "source": [
     "# # Install package\n",
-    "# !pip install unstructured"
+    "!pip install unstructured[local-inference]\n",
+    "!pip install \"detectron2@git+https://github.com/facebookresearch/detectron2.git@v0.6#egg=detectron2\"\n",
+    "!pip install layoutparser[layoutmodels,tesseract]"
    ]
   },
   {
@@ -29,7 +31,12 @@
    "source": [
     "# # Install other dependencies\n",
     "# # https://github.com/Unstructured-IO/unstructured/blob/main/docs/source/installing.rst\n",
-    "# !brew install libmagic"
+    "# !brew install libmagic\n",
+    "# !brew install poppler\n",
+    "# !brew install tesseract\n",
+    "# # If parsing xml / html documents:\n",
+    "# !brew install libxml2\n",
+    "# !brew install libxslt"
    ]
   },
   {
@@ -149,6 +156,72 @@
     "docs[:5]"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "7874d01d",
+   "metadata": {},
+   "source": [
+    "## PDF Example\n",
+    "\n",
+    "Processing PDF documents works exactly the same way. Unstructured detects the file type and extracts the same types of `elements`. "
+   ]
+  },
+  
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "8ca8a648",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "!wget  https://raw.githubusercontent.com/Unstructured-IO/unstructured/main/example-docs/layout-parser-paper.pdf -P \"../../\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "686e5eb4",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "loader = UnstructuredFileLoader(\"../../layout-parser-paper.pdf\", mode=\"elements\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "f8348ca0",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "docs = loader.load()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "6ec859d8",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[Document(page_content='LayoutParser : A Unified Toolkit for Deep Learning Based Document Image Analysis', lookup_str='', metadata={'source': '../../layout-parser-paper.pdf'}, lookup_index=0),\n",
+       " Document(page_content='Zejiang Shen 1 ( (ea)\\n ), Ruochen Zhang 2 , Melissa Dell 3 , Benjamin Charles Germain Lee 4 , Jacob Carlson 3 , and Weining Li 5', lookup_str='', metadata={'source': '../../layout-parser-paper.pdf'}, lookup_index=0),\n",
+       " Document(page_content='Allen Institute for AI shannons@allenai.org', lookup_str='', metadata={'source': '../../layout-parser-paper.pdf'}, lookup_index=0),\n",
+       " Document(page_content='Brown University ruochen zhang@brown.edu', lookup_str='', metadata={'source': '../../layout-parser-paper.pdf'}, lookup_index=0),\n",
+       " Document(page_content='Harvard University { melissadell,jacob carlson } @fas.harvard.edu', lookup_str='', metadata={'source': '../../layout-parser-paper.pdf'}, lookup_index=0)]"
+      ]
+     },
+     "execution_count": 1,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "docs[:5]"
+   ]
+  },  
   {
    "cell_type": "code",
    "execution_count": null,