Make auto-refresh opt-in

[steinybot]

Hi,

Thanks for creating the plugin.

I have a major gripe with auto updates. It is extremely intrusive for the very rare case where I actually want to use sdkman autocompletion. So many times I think my shell setup is broken just because this plugin has decided to go and refresh a whole lot of things.

Compounding this issue is that it plays really poorly with powerlevel10k and instant prompt where there is no output and so I have no idea what is going on when I first open my terminal for the day.

I think it would be better to make auto-refresh opt-in instead. I don't run sdkman manually a lot so having it refresh every 12 hours is a bit over the top, especially since it takes so long. Ideally it would only refresh on demand rather than in advance, if that is even possible.

[manuelprinz]

I came across this plug-in a couple of days ago and had the same issue. I think it is possible to avoid it altogether, partially demonstrated in #19. I will have a look at the rest, but am by no means a ZSH completion expert. Feedback welcome!