Option to use onSuccess event

[passion4code]

Is your feature request related to a problem? Please describe.
Is there a world where this plugin can work by using the onSuccess event instead of the onPostBuild event? Perhaps with an input configuration?

It would be nice to not block a deploy or slow a build down as an option for this type of an audit, particularly for sites with thousands of pages that would need to be parsed.

Describe the solution you'd like
Input configuration to toggle which event to listen to for this build plugin; onSuccess or onPostBuild

Describe alternatives you've considered
I've considered forking this repo and testing out if it works, but it would not be good to split from the source for a single feature.

Additional context
No additional context, other than I am very unfamiliar with the ins and outs of Netlify plugins.