feat: auto-quit vim if oil is closed as last buffer

[cdmill]

Added a simple feature that will auto-quit vim if oil is closed and there are no other buffers open. I added an option to config.lua to opt-in to this behavior.

[stevearc]

I think this is a fine customization, but it should be done by passing in options to the function rather than a config option. The oil.close function should take an option table with something like close_if_last_buf as the parameter. Then the close action should be reworked to accept the same options, similar to how actions.cd accepts options.

[cdmill]

I chose exit_if_last_buf to make it more clear that it is separate from oil.close but if you prefer 'quit' or 'close' than I can resubmit!

[stevearc]

Just a couple nits left

[cdmill]

Any update on this?

[stevearc]

LGTM!