Readme fixes + pytorch3d nerf logo gif

Summary: Fixes to Readme in NeRF

Reviewed By: nikhilaravi

Differential Revision: D26205882

fbshipit-source-id: 73e4d727f6e6c96fa7af7d2b917acdeaf990091c

Author: davnov134

.github/nerf_project_logo.gif

@@ -3,6 +3,9 @@ Neural Radiance Fields in PyTorch3D
 
 This project implements the Neural Radiance Fields (NeRF) from [1].
 
+<img src="https://raw.githubusercontent.com/facebookresearch/pytorch3d/master/.github/nerf_project_logo.gif" width="600" height="300"/>
+
+
 Installation
 ------------
 1) [Install PyTorch3D](https://github.com/facebookresearch/pytorch3d/blob/master/INSTALL.md)