also return value for `$.select`

it feels more natural to return value for selection:

```ts
const selectedBranch: string = await $.select({
    message: "Select a branch:",
    options: branches,
})
```

or we could return an option:
```ts
> await $.select({
...     message: "Select a branch:",
...     options: branches,
... })
{ index: 10, value: "main" }
```