## insertion_sort
### Instructions
Implement the insertion-sort algorithm by creating a function named `insertion_sort` . It should execute the iterations of the algorithm **up to** the number indicated by `steps` . See the **Usage** for more information.
The insertion-sort algorithm sorts an array of size `n` in ascending order.
1. Iterates over the slice from `slice[1]` to `slice[n]` .
2. Compares the current element (`slice[key]`) to its predecessor (`slice[key-1]`).
3. If `slice[key]` is smaller than `slice[key-1]` , then `slice[key]` is compared to `slice[key-2]` and so on.
4. All of the elements with values greater than `slice[key]` will need to be shifted over, to fit the value at `slice[key]` into its new position.
A step-by-step example of insertion-sort:
**Figure 1** - Step by step execution of the algorithm insertion sort
### Expected Function
```rust
pub fn insertion_sort(slice: & mut [i32], steps: usize) {
}
```
### Usage
Here is a possible program to test your function,
```rust
fn main() {
let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
// executes the first iteration of the algorithm
insertion_sort(& mut target, 1);
println!("{:?}", target);
let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
let len = target.len();
// executes len - 1 iterations of the algorithm
// i.e. sorts the slice
insertion_sort(& mut target, len - 1);
println!("{:?}", target);
}
```
And its output:
```console
$ cargo run
[3, 5, 7, 2, 1, 6, 8, 4]
[1, 2, 3, 4, 5, 6, 7, 8]
$
```
