Added install instructions to readme

Author: leopiney

README.md

@@ -9,6 +9,16 @@
 `tensor-safe` is a dependently typed framework to define deep learning models which structure is verified on
 compilation time. If the models are valid, these can be compiled to Keras framework in Python or JavaScript.
 
+## Install instructions
+
+1. Install `tensor-safe` executable with `cabal new-install`
+
+   `cabal new-install tensor-safe`
+
+2. Install `tensor-safe` library
+
+   `cabal new-install tensor-safe --lib`
+
 ## Building instructions and development tools
 
 1. Install `ghc-mod`, `hpack` and `stylish-haskell` with `stack install`