Updated Hello World (markdown)

Hello-World.md

@@ -1,4 +1,3 @@
-``` c
 #include <stdlib.h>
 #include <stdio.h>
 
@@ -6,7 +5,7 @@
 #include <mruby.h>
 #include <mruby/proc.h>
 #include <mruby/data.h>
-// to be eventually replaced by #include <mruby/compile.h>
+// to be replaced by #include <mruby/compile.h>
 #include <compile.h>
 
 int main(void)
@@ -14,15 +13,14 @@ int main(void)
   struct mrb_parser_state *p;
   mrb_state *mrb = mrb_open();
   char code[] = "p 'hello world!'";
-  printf("Executing code with mruby!\n");
+  printf("Executing Ruby code from C!\n");
 
   p = mrb_parse_string(mrb, code);
   int n;
   n = mrb_generate_code(mrb, p->tree);
   mrb_run(mrb, mrb_proc_new(mrb, mrb->irep[n]), mrb_top_self(mrb));
   if (mrb->exc) {
-   mrb_funcall(mrb, mrb_nil_value(), "p", 1, mrb_obj_value(mrb->exc));
+    mrb_p(mrb, mrb_obj_value(mrb->exc));
   }
   return 0;
 }
-```