update README

Author: nikomatsakis

README.md

@@ -6,21 +6,10 @@ and develop it as an official part of the language definition.
 
 ## Quickstart guide
 
-The quickstart guide can be found [in the documentation](https://nikomatsakis.github.io/a-mir-formality/docs/setup)
+Like any Rust project:
 
-## Tool
-
-For the time being, the model is implemented in [PLT Redex](https://redex.racket-lang.org/).
-PLT Redex was chosen because it is ridiculously accessible and fun to use.
-It lets you write down type system rules and operational semantics and then execute them,
-using a notation that is very similar to what is commonly used in published papers.
-You can also write collections of unit tests and fuzz your model by generating test programs automatically.
-
-The hope is that PLT Redex will prove to be a sufficiently accessible tool
-that many Rust contributors will be able to understand, play with, and extend the model.
-
-One downside of PLT Redex is that it doesn't scale naturally to performing proofs.
-We may choose to port the model to another system at some point, or maintain multiple variants.
+* Clone
+* `cargo test --all`
 
 <!-- TODO -->
 <!-- ## Structure of the repository -->