Make dropdown trigger type with hover

[zoltanszogyenyi]

We should add an option to trigger the dropdown menu by more trigger types, such as hover, not just click.

It should be accessible via a data attribute such as data-dropdown-trigger="hover" where by default it's click.

This should be also added as an option for the Dropdown object.

File to be modified: https://github.com/themesberg/flowbite/blob/develop/src/components/dropdown.js

We should also update the docs and show a "hover" dropdown example too: https://flowbite.com/docs/components/dropdowns/