docs: update for fuste main usage.

Author: l-monninger

README.md

@@ -36,19 +36,18 @@ pub fn add(a: u32, b: u32) -> u32 {
 	a + b
 }
 
-fuste::entry! {
-	fn main() -> Result<(), ()> {
-		let mut j = 0;
-		for i in 0..10 {
-			assert_eq!(i, i);
-			j += i;
-			j = add(j, i);
-			println!("Hello, world!");
-			println!("i: {}, j: {}", i, j);
-		}
-
-		Ok(())
+#[fuste::main]
+fn main() -> Result<(), ()> {
+	let mut j = 0;
+	for i in 0..10 {
+		assert_eq!(i, i);
+		j += i;
+		j = add(j, i);
+		println!("Hello, world!");
+		println!("i: {}, j: {}", i, j);
 	}
+
+	Ok(())
 }
 ```
 6. Run!