Pytorch3d: Undersampled images in documentation

[eliemichel]

Particularily transformations_overview.png is close to being unreadable. On other images it is more a problem of some lines using a very small font.

[gkioxari]

Thank you for the feedback. We will try to release higher resolution images.

[nikhilaravi]

Thanks for pointing this out and for reading the documentation! I will update the images!

[gkioxari]

We have updated the images with higher resolution versions. Closing this!