### What it does
Checks for using `x.get(0)` instead of
`x.first()`.

### Why is this bad?
Using `x.first()` is easier to read and has the same
result.

### Example
```
let x = vec![2, 3, 5];
let first_element = x.get(0);
```

Use instead:
```
let x = vec![2, 3, 5];
let first_element = x.first();
```