Fix typo explain target in install

Author: davesnx

docs/installation.md

@@ -60,7 +60,7 @@ opam install melange dune reason reason-react reactjs-jsx-ppx -y
 
 2. Enable melange inside dune under a `dune-project` file in the root of your project with the following:
 ```sh
-(dune lang 3.8)
+(lang dune 3.8)
 (using melange 0.1)
 ```
 
@@ -75,6 +75,8 @@ Check [dune docs](https://dune.readthedocs.io/en/latest/melange.html) for all fi
   (preprocess (pps reactjs-jsx-ppx)))
 ```
 
+The target name is the name of the folder where the compiled code will live and also an "alias" to run the build commands (see below).
+
 4. Run those commands to build your code:
 
 ```sh