make git commit hash available at compile time

src/main.rs

@@ -160,6 +160,7 @@ fn main() -> Result<()> {
             text += format!("\nYou gained {} experience.", game.get_player().get_experience()).as_str();
             text += format!("\nYou collected {} gold.", game.get_player().get_gold()).as_str();
             text += format!("\nYou played {} seconds.", playtime.as_secs()).as_str();
+            text += format!("\nYou played game version '{}'.", env!("GIT_HASH")).as_str();
             let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
             frame.render_widget(paragraph, area);
         });
@@ -171,7 +172,6 @@ fn main() -> Result<()> {
             }
         }
     }
-
     stdout().execute(LeaveAlternateScreen)?;
     disable_raw_mode()?;
     Ok(())