Configure a delay for live_blame

[tenstan]

From what I understand, the virtual text of live_blame only gets rendered when the CursorHold event is triggered. The delay of this event is based on the updatetime vim option, which is 4 seconds by default.

4 seconds is a very long time before the virtual text gets rendered in my opinion. While updatetime can be overridden of course, I don't like the idea that a global needs to be modified in order to change when the virtual text is rendered.

I think it would be a good idea to allow people to configure the delay until the virtual text is rendered, for example:

require('vgit').setup({
    live_blame = {
        enabled = true,
        delay = 1000     -- NEW: Render the live_blame virtual text after 1000 ms
    }
})

I'm willing to submit a PR if this sounds like a good idea.