Improve: Browser locator warnings

[inancgumus]

We display a warning when users want to use non-locator methods. For example:

{{< admonition type="warning" >}}

Use [`locator.setChecked(checked [, options])`](https://grafana.com/docs/k6/<K6_VERSION>/javascript-api/k6-browser/locator/setchecked/) instead.

{{< /admonition >}}

@heitortsergent suggests:

It would be nice to provide a reason why the user should be using the locator.setChecked instead.

So, the idea is to improve these warnings with a valid reason. The solution could be redirecting users to an article like this one.