tutorial fixes from #336. Wheels with cuda10.1.

Summary:
Add a document to explain how to run the tutorials.
Fix API of TexturesVertex in fit_textured_mesh.
Prepare cuda 10.1 wheels (not 10.2) for linux to be available on pypi - this matches what colab has.
Change the tutorials to use these new wheels.

Reviewed By: gkioxari

Differential Revision: D23324479

fbshipit-source-id: 60e92a3f46a2d878f811b7703638f8d1dae143d9

docs/tutorials/bundle_adjustment.ipynb

@@ -81,7 +81,11 @@
    "outputs": [],
    "source": [
     "!pip install torch torchvision\n",
-    "!pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "import sys\n",
+    "if torch.__version__=='1.6.0+cu101' and sys.platform.startswith('linux'):\n",
+    "    !pip install pytorch3d\n",
+    "else:\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {