Vito migration guide

So I updated the fresco dependency the other day, and it seems like `SimpleDraweeView` is now deprecated, recommending to use vito instead. However, the information in the documentation is rather vague so after looking it up I found #2781 which helped clarify things a bit, but a lot of questions still remain.

1. It seems like vito is completely orthogonal to regular fresco. It seems to use different classes, different everything like a rewrite. Is that the case?
2. Which dependencies am I supposed to depend on. There are dozens of vito-* dependencies. How do they relate to other dependencies like `animated-webp` or `imagepipeline-okhttp3`?
3. Why do I get compilation errors when I include too few dependencies? I started with `vito-view` and got compilation errors just from using it until I also added `vito-source` and `vito-options`.

This is all really confusing to me, especially because the fresco website with all of the documentation continues to use `SimpleDraweeView`, even though this class is deprecated. I'm looking forward to get some answers from you.

Start with the existing Fresco website documentation, the references to SimpleDraweeView, and issue #2781. Compare the current guidance with the Vito dependencies and answer the three dependency and migration questions; done means the documentation clearly explains the transition and no longer relies only on deprecated examples.

Written by the indexing model from the issue text.