Added enumerate function in control flow.md - for loop section (#65)

* Added enumerate function in for loop

* Update a10.control-flows.md

---------

Co-authored-by: Dumindu Madunuwan <[email protected]>

Author: Akshat-Vashisht

content/en/docs/a10.control-flows.md

@@ -271,11 +271,15 @@ for b in 0..6 {
 // Working with arrays/vectors
 let group : [&str; 4] = ["Mark", "Larry", "Bill", "Steve"];
 
-for n in 0..group.len() { // group.len() = 4 -> 0..4 👎 check group.len()on each iteration
+for n in 0..group.len() { // group.len() = 4 -> 0..4 👎 check group.len() on each iteration
   println!("Current Person : {}", group[n]);
 }
 
 for person in group.iter() { // 👍 group.iter() turn the array into a simple iterator
   println!("Current Person : {}", person);
 }
+
+for (index, person) in group.iter().enumerate() { // 💡 group.iter().enumerate() helps to read both the current index (starting from zero) and the value
+  println!("Person {} : {}", index, person);
+}
 ```