Improve runtime docs of TriggerEffectItem

[SWeini]

Please take a look at TriggerEffectItem.

It is lacking all the extra fields that exist depending on the type, which are well documented for prototype stage. I don't know whether it's worth duplicating all that information, but it means that working with these in runtime stage currently doesn't have proper tooling support (e.g. using FMTK/LuaLS).

[Bilka]

I've added the missing fields for TriggerEffectItem, TriggerDelivery and TriggerItem to the runtime docs for the next release.