Add options leading & trailing

[r4mbo7]

Hello,

Here is a proposal to add options to fire an event on the leading edge of the timeout.

The current behavior is unchanged if the options are not set (the event is fire on the trailing edge of the timeout).

Options inspired from https://lodash.com/docs#debounce.

The package.json has to be updated for a new package version to be released.

Thanks 👋

[r4mbo7]

Hi @hopsoft ! Thanks for your approval. Do you plan to do a new release of the npm package soon ?

[hopsoft]

Yes as soon as I get some bandwidth to put attention back on this lib. Thanks for being patient.