Feature request description
I would like the player get advancement event to be added to the Crafttweaker event manager. http://docs.blamejared.com/en/#Vanilla/Events/IEventManager/

Feature request reason
It would allow people to use achievement unlocks as triggers for their scripts.

Feature request dependencies
This feature only requires vanilla and modded achievements to work. Any mod that adds achievements or just plain vanilla minecraft would add all the support it needs, as you can create advancements with data packs in minecraft or with mods like Triumph.