Print result of main for js target

.gitignore

@@ -1,2 +1,3 @@
 target/
-.vscode/
+.vscode/
+examples_out/

examples/hello_world.sb

@@ -1,5 +1,5 @@
 fn main() {
-    return;
+    return "Hello World";
 }
 
 fn fib() {}

src/generator/js.rs

@@ -11,7 +11,8 @@ impl Generator for JsGenerator {
             .map(|f| generate_function(f))
             .collect();
 
-        code += "main()";
+        // Until we have a stdlib, it should suffice to print the result of main to stdout
+        code += "console.log(main())";
 
         return code;
     }