Provide system_breadcrumb_alter for structured data output

I think this change is fairly straightforward and will be useful to other users of Easy Breadcrumb. This is the first contribution I've made to the Drupal 9 world so I hope I've got it right.

Greg Boggs → made their first commit to this issue’s fork.

Thanks for the fix to the alter hook!

I think there's a setting to include taxonomy in the crumbs, but it's probably not configurable enough for your use case because it doesn't let you choose a field to use and content types to apply it to.

closing since the MR was merged and this was just not closed