Revise docs.

doc/src/language/loop.md

@@ -13,8 +13,11 @@ let x = 10;
 
 loop {
     x = x - 1;
+
     if x > 5 { continue; }  // skip to the next iteration
+
     print(x);
+
     if x == 0 { break; }    // break out of loop
 }
 ```