Update env.rs (#420)

* Update env.rs

The book says "There is no need to execute the file for Windows users. It is only created to show the modified environment variables.". This appears to be out of date.

* Update src/env.rs to simpler help message.

Co-authored-by: Sergio Gasquez Arcos <sergio.gasquez@gmail.com>

* fix: Remove line

---------

Co-authored-by: Sergio Gasquez Arcos <sergio.gasquez@gmail.com>

src/env.rs

@@ -164,6 +164,8 @@ pub fn print_post_install_msg(export_file: &Path) -> Result<(), Error> {
             "\tA file was created at '{}' showing the injected environment variables",
             export_file.display()
         );
+        println!("\tIf you get still get errors, try manually adding the environment variables by running '{}'", export_file.display()
+        );
     }
     #[cfg(unix)]
     if cfg!(unix) {