Feature: Disable Prev/Next on First/Last

[FNGR2911]

First of fall: thank you for this pretty nice package.

A small idea for UX improvement: disable or display: none prev/next buttons, when there is no prev/next (when you are on first/last) image.

I'll try to make a PR, but at the moment I can't get the npm modules installed (bunch of errors).

Is there a need for this little improvement?

Best regards, Matti

[beatep]

+1! I was wondering about that myself.