Update readme

Author: ismailmustafa

README.md

@@ -10,7 +10,7 @@ The language client requires you to manually install the [HIE](https://github.co
 
 ```bash
 $ git clone https://github.com/haskell/haskell-ide-engine --recursive
-$ cd haskell-ide-engine && make build
+$ cd haskell-ide-engine && make build-all
 ```
 
 Alternatively you can just `stack install`, but `make build` will give you the best setup.