Keep track of the parent element selector

When using `cyclope` as a child command, form the element selector automatically

```js
// get an image of the todos element
// instead of this
cy.get('.todos').cyclope('todos.png', {
elementSelector: '.todos',
})
// automatically limit the image to ".todos"
cy.get('.todos').cyclope('todos.png')
```

Start from the Cypress child-command example using `cy.get('.todos').cyclope(...)` and trace how the command handles its options. Verify that omitting `elementSelector` uses the parent `.todos` selector while an explicit selector remains supported; the example should produce an image limited to `.todos`.

Written by the indexing model from the issue text.